1. The Four types of output are text (usually used in reference to a computer application, a text-based application is one whose primary input and output are based on text rather than graphics or sound. This does not mean that text-based applications do not have graphics or sound, just that the graphics or sound are secondary to the text), graphics(created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware), audio(sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion (ADC), digital-to-analog conversion (DAC), digital storage, processing and transmission components. The primary usefulness of digital audio is the ability to store, retrieve and transmit signals without any loss of quality), and video(the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion).

2. A liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly.

They are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs have displaced cathode ray tube (CRT) displays in most applications. They are usually more compact, lightweight, portable, less expensive, more reliable, and easier on the eyes. They are available in a wider range of screen sizes than CRT and plasma displays, and since they do not use phosphors, they cannot suffer image burn-in.

LCDs are more energy efficient and offer safer disposal than CRTs. Its low electrical power consumption enables it to be used in battery-powered electronic equipment. It is an electronically modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. The earliest discovery leading to the development of LCD technology, the discovery of liquid crystals, dates from 1888. By 2008, worldwide sales of televisions with LCD screens had surpassed the sale of CRT units. Plasma display screens are made from glass, which reflects more light than the material used to make an LCD screen. This causes glare from reflected objects in the viewing area. Companies such as Panasonic coat their newer plasma screens with an anti-glare filter material. Currently, plasma panels cannot be economically manufactured in screen sizes smaller than 32 inches. Although a few companies have been able to make plasma EDTVs this small, even fewer have made 32in plasma HDTVs. With the trend toward larger and larger displays, the 32in screen size is rapidly disappearing. Though considered bulky and thick compared to their LCD counterparts, some sets such as Panasonic's Z1 and Samsung's B860 series are as slim as one inch thick making them comparable to LCDs in this respect. Competing display technologies include CRT, OLED, LCD, DLP, SED, LED, FED, and QLED. High-definition television (or HDTV) is video that has resolution substantially higher than that of traditional television systems (standard-definition TV, or SDTV, or SD). HDTV has one or two million pixels per frame, roughly five times that of SD. Early HDTV broadcasting used analog techniques, but today HDTV is digitally broadcast using video compression. Some personal video recorders (PVRs) with hard disk storage but without high-definition tuners are described as "HD", for "Hard Disk", which can be a cause of confusion.

3. Computer cases usually include sheet metal enclosures for a power supply unit and drive bays, as well as a rear panel that can accommodate peripheral connectors protruding from the motherboard and expansion slots. Most cases also have a power button or switch, a reset button, and LEDs to indicate power status as well as hard drive and network activity. Some cases include built-in I/O ports (such as USB and headphone ports) on the front of the case. Such a case will also include the wires needed to connect these ports, switches and indicators to the motherboard.

Major component

• The motherboard is usually screwed to the case along its largest face, which could be the bottom or the side of the case depending on the form factor and orientation.
• Form factors such as ATX provide a back panel with cut-out holes to expose I/O ports provided by integrated peripherals, as well as expansion slots which may optionally expose additional ports provided by expansion cards.
• The power supply unit is often housed at the top rear of the case; it is usually attached with four screws to support its weight.
• Most cases include drive bays on the front of the case; a typical ATX case includes both 5.25" and 3.5" bays. In modern computers, the former are used mainly for optical drives, while the latter are used for hard drives, floppy drives, and card readers.
• Buttons and LEDs are typically located on the front of the case; some cases include additional I/O ports, temperature and/or processor speed monitors in the same area.
• Vents are often found on the front, back, and sometimes on the side of the case to allow cooling fans to be mounted via surrounding threaded screw holes.

Internal access

Tower cases have either a single side panel which may be removed in order to access the internal components or a large cover that saddles the chassis. Traditionally, most computer cases required screws to hold components and panels in place (i.e. motherboard, PSU, drives, and expansion cards). Recently there is a trend toward "screwless" cases, in which components are held together with snap-in plastic rails, thumbscrews, and other methods that do not require tools; this facilitates quick assembly and modification of computer hardware.

4. The fundamental operation of most CPUs, regardless of the physical form they take, is to execute a sequence of stored instructions called a program. The program is represented by a series of numbers that are kept in some kind of computer memory. There are four steps that nearly all CPUs use in their operation: fetch, decode, execute, and writeback. The first step, fetch, involves retrieving an instruction (which is represented by a number or sequence of numbers) from program memory. The location in program memory is determined by a program counter (PC), which stores a number that identifies the current position in the program. After an instruction is fetched, the PC is incremented by the length of the instruction word in terms of memory units.^[5] Often, the instruction to be fetched must be retrieved from relatively slow memory, causing the CPU to stall while waiting for the instruction to be returned. This issue is largely addressed in modern processors by caches and pipeline architectures (see below). The instruction that the CPU fetches from memory is used to determine what the CPU is to do. In the decode step, the instruction is broken up into parts that have significance to other portions of the CPU. The way in which the numerical instruction value is interpreted is defined by the CPU's instruction set architecture (ISA). Often, one group of numbers in the instruction, called the opcode, indicates which operation to perform. The remaining parts of the number usually provide information required for that instruction, such as operands for an addition operation. Such operands may be given as a constant value (called an immediate value), or as a place to locate a value: a register or a memory address, as determined by some addressing mode. In older designs the portions of the CPU responsible for instruction decoding were unchangeable hardware devices. However, in more abstract and complicated CPUs and ISAs, a microprogram is often used to assist in translating instructions into various configuration signals for the CPU. This microprogram is sometimes rewritable so that it can be modified to change the way the CPU decodes instructions even after it has been manufactured. After the fetch and decode steps, the execute step is performed. During this step, various portions of the CPU are connected so they can perform the desired operation. If, for instance, an addition operation was requested, the arithmetic logic unit (ALU) will be connected to a set of inputs and a set of outputs. The inputs provide the numbers to be added, and the outputs will contain the final sum. The ALU contains the circuitry to perform simple arithmetic and logical operations on the inputs (like addition and bitwise operations). If the addition operation produces a result too large for the CPU to handle, an arithmetic overflow flag in a flags register may also be set. The final step, writeback, simply "writes back" the results of the execute step to some form of memory. Very often the results are written to some internal CPU register for quick access by subsequent instructions. In other cases results may be written to slower, but cheaper and larger, main memory. Some types of instructions manipulate the program counter rather than directly produce result data. These are generally called "jumps" and facilitate behavior like loops, conditional program execution (through the use of a conditional jump), and functions in programs. Many instructions will also change the state of digits in a "flags" register. These flags can be used to influence how a program behaves, since they often indicate the outcome of various operations. For example, one type of "compare" instruction considers two values and sets a number in the flags register according to which one is greater. This flag could then be used by a later jump instruction to determine program flow. After the execution of the instruction and writeback of the resulting data, the entire process repeats, with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter. If the completed instruction was a jump, the program counter will be modified to contain the address of the instruction that was jumped to, and program execution continues normally. In more complex CPUs than the one described here, multiple instructions can be fetched, decoded, and executed simultaneously. This section describes what is generally referred to as the "classic RISC pipeline", which in fact is quite common among the simple CPUs used in many electronic devices (often called microcontroller). It largely ignores the important role of CPU cache, and therefore the access stage of the pipeline.

5. A bit (a contraction of binary digit) is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states. These may be the two stable states of a flip-flop, two positions of an electrical switch, two distinct voltage or current levels allowed by a circuit, two distinct levels of light intensity, two directions of magnetization or polarization, etc. There are several units of information which are defined as multiples of bits, such as byte (8 bits), kilobit (either 1000 or 2¹⁰ = 1024 bits), megabyte (either 8000000 or 8×2²⁰ = 8388608bits), etc. Computers usually manipulate bits in groups of a fixed size, conventionally named "words". The number of bits in a word varies with the computer model; typically between 8 to 80 bits; or even more in some specialized machines. The International Electrotechnical Commission's standard IEC 60027 specifies that the symbol for binary digit should be "bit", and this should be used in all multiples, such as "kbit" (for kilobit).^[5] However, the letter "b" (in lower case) is widely used too. The letter "B" (upper case) is both the standard and customary symbol for byte. In telecommunications (including computer networks), data transfer rates are usually measured in bits per second (bit/s) or its multiples, such as kbit/s. (This unit is not to be confused with baud.)

6. Types of Application Software:

Word Processing Software: Allows users to create, edit a document. Example: MS Word, Word Pad etc.

Spreadsheet Software: Allows users to create document and perform calculation. Example: Excel, Lotus1-2-3 etc.

Database Software: Allows users to store and retrieve vast amount of data. Example: MS Access, MySQL, Oracle etc.

Presentation Graphic Software: Allows users to create visual presentation. Example: MS Power Point

Multimedia Software: Allows users to create image, audio, video etc. Example: Real Player, Media Player etc.

7. JasperSoft: The Most Widely Used Open Source Business Intelligence Software

JasperReports is part of the JasperSoft open source business intelligence suite. JasperReports offers a range of reporting and charting features.

Features:

• Adhoc Reporting – With JasperReports you can generate ad hoc reports and queries.
• Drag and Drop – Reports can be put together quickly using drag and drop features, with no need for programming knowledge.
• Data sources – Data can be imported from most file formats, including Excel, XML, relational, Hibernate and EJB
• Automatic Reporting – JasperReports can be programmed to generate and distribute reports at given intervals.
• Dashboard Designer – JasperReports comes with a dashboard designer, which also uses drag and drop features.

8. Application software, also known as an application or an "app", is computer software designed to help the user to perform singular or multiple related specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with documents. Apps may be bundled with the computer and its system software, or may be published separately. Some users are satisfied with the bundled apps and need never install one.

Application software is contrasted with system software and middleware, which manage and integrate a computer's capabilities, but typically do not directly apply them in the performance of tasks that benefit the user. The system software serves the application, which in turn serves the user. Similar relationships apply in other fields. For example, a shopping mall does not provide the merchandise a shopper is seeking, but provides space and services for retailers that serve the shopper. Rail tracks similarly support trains, allowing the trains to transport passengers. Application software applies the power of a particular computing platform or system software to a particular purpose. Some apps such as Microsoft Office are available in versions for several different platforms; others have narrower requirements and are thus called, for example, a Geography application for Windows or an Android application for education or Linux gaming. Sometimes a new and popular application arises which only runs on one platform, increasing the desirablity of that platform. This is called a killer application.

9. The history of the Internet starts in the 1950s and 1960s with the development of computers. This began with point-to-point communication between mainframe computers and terminals, expanded to point-to-point connections between computers and then early research into packet switching. Packet switched networks such as ARPANET, Mark I at NPL in the UK, CYCLADES, Merit Network, Tymnet, and Telenet, were developed in the late 1960s and early 1970s using a variety of protocols. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks. In 1982 the Internet Protocol Suite (TCP/IP) was standardized and the concept of a world-wide network of fully interconnected TCP/IP networks called the Internet was introduced. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) developed the Computer Science Network (CSNET) and again in 1986 when NSFNET provided access to supercomputer sites in the United States from research and education organizations. The ARPANET was decommissioned in 1990. Commercial internet service providers (ISPs) began to emerge in the late 1980s and 1990s and the Internet was commercialized in 1995 when NSFNET was decommissioned, removing the last restrictions on the use of the Internet to carry commercial traffic. Since the mid-1990s the Internet has had a drastic impact on culture and commerce, including the rise of near instant communication by electronic mail, instant messaging, Voice over Internet Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web with its discussion forums, blogs, social networking, and online shopping sites. The research and education community continues to use advanced networks such as NSF's very high speed Backbone Network Service (vBNS) and Internet2. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1-Gbps, 10-Gbps, or more. The Internet continues to grow, driven by ever greater amounts of online information and knowledge, commerce, entertainment and social networking.

10. 1. CATEGORIZING STORAGE DEVICES

• Storage devices hold data, even when the computer is turned of.

• The physical material that actualy holds data is caled a storage medium. The surface of a floppy disk is a storage medium.

• The hardware that writes data to or reads data from a storage medium is caled a storage device. A floppy disk drive is a storage device.

• The two primary storage technologies are magnetic and optical.

The primary types of magnetic storage are:

• Disketes (floppy disks)

• Hard disks

• High-capacity floppy disks

• Disk cartridges

• Magnetic tape

The primary types of optical storage are:

• Compact Disk Read-Only Memory (CD-ROM)

• Digital Video Disk Read-Only Memory (DVD-ROM)

o CD-Recordable (CD-R)

• CD-Rewritable (CD-RW)

• PhotoCD

2. MAGNETIC STORAGE DEVICES

- How Magnetic Storage Works

• A magnetic disk's medium contains iron particles, which can be polarized—given a magnetic charge—in one of two directions.

• Each particle's direction represents a 1 (on) or 0 (of), representing each bit of data that the CPU can recognize.

• A disk drive uses read/write heads containing electromagnets to create magnetic charges on the medium.

-Formatting

• Before a magnetic disk can be used, it must be formated—a process that maps the disk's surface and determines how data wil be stored.

• During formating, the drive creates circular tracks around the disk's surface, then divides each track into sectors.

• The OS organizes sectors into groups, caled clusters, then tracks each file's location according to the clusters it occupies.

-Disk Areas

When a disk is formated, the OS creates four areas on its surface:

• Boot sector – stores the master boot record, a smalL program that runs when you first start (boot) the computer.

• File alocation table (FAT) – a log that records each file's location and each sector's status

• Root folder – enables the user to store data on the disk in a logical way

• Data area – the portion of the disk that actualy holds data

-Diskettes

• Diskete drives,alsoknown as floppy disk drives, read and write to disketes (caled floppy disks or floppies).

• Disketes are used to transfer files between computers, as a means for distributing software,and as a backup medium.

• •Disketes come in two sizes: 5.25-inch and 3.5-inch.

-Hard Disks

• Hard disks use multiple platers, stacked on a spindle. Each plater has two read/write heads, one for each side.

• Hard disks use higher-quality media and a faster rotational speed than disketes.

• Removable hard disks combine high capacity with the convenience of disketes.

-Disk Capacities

• Disketes are available in diferent capacities, but the most common store 1.44 MB.

• Hard disks storelarge amounts of data. New PCs feature hard disks with capacities of 10 GB and higher.

-Other Magnetic Storage Devices

• High-capacity floppy disks ofer capacities up to 250 MB and the portability of standard floppy disks.

• Disk cartridges are like smal removable hard disks, and can store up to 2 GB.

• Magnetic tape systems ofer very slow data access, but provide large capacities and low cost.

3. OPTICAL STORAGE DEVICES

-How Optical Storage Works

• An optical disk is a high-capacity storage medium.

• An optical drive uses reflected light to read data.

• To store data, the disk's metal surface is covered with tiny dents (pits) and flat spots (lands), which cause light to be reflected diferently.

• When an optical drive shines light into a pit, the light cannot be reflected back. This represents a bit value of 0 (of). A land reflects light back to its source, representing a bit value of 1 (on).

-CD-ROM

• In PCs, the most commonly usedoptical storage technology is called Compact Disk Read-Only Memory (CD-ROM).

• A standard CD-ROM disk can store up to 650 MB of data, or about 70 minutes of audio.

• Once data is writen toa standard CD-ROM disk, the data cannot be altered or overwriten.

-CD-ROM Speeds and Uses

• Early CD-ROM drives were caled single speed, and read data at a rate of 150 KBps. (Hard disks transfer data at rates of 5 – 15 MBps).

• CD-ROM drives now can transfer data at speeds of up to 7800 KBps. Data transfer speeds are geting faster.

• CD-ROM is typicaly used to store software programs. CDs can store audio and video data, as wel as text and program instructions.

-DVD-ROM

• A variation of CD-ROM is caled Digital Video Disk Read-Only Memory (DVD-ROM), and is being used in place of CD-ROM in many newer PCs.

• Standard DVD disks store up to 9.4 GB of data—enough to store an entire movie. Dual-layer DVD disks can store up to 17 GB.

• DVD disks can store so much data because both sides of the disk are used, along with sophisticated data compression technologies.

-Other Optical Storage Devices

• A CD-Recordable (CD-R) drive lets you record your own CDs, but data cannot be overwriten once it is recorded to the disk.

• A CD-Rewritable (CD-RW) drive lets you record a CD, then write new data over the already recorded data.

• PhotoCD technology is used to store digital photographs.