Computer Notes
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The document discusses computer hardware and software. It defines computer hardware as the physical parts of a computer like input, output, storage, and processing devices. It also defines computer software as programs that enable users to interact with the computer and its hardware. The document then describes different types of both system software like operating systems and application software like word processors and spreadsheets. It provides examples and definitions for many common computer hardware components and software programs.
Computer Notes
- 1. 6/15/2016 Skill Development By Ehsan Khan Ehsan Khan UNVERSITY LAW COLLEGE QUETTA
- 2. 1 | P a g e Computer Computer is an electronic device/machine used for calculate something. Or Computer is a Latin word “compute” which means to calculate. Or Computer is a device that covert data into information. Acronym of computer C Common. O operating. M Machine. P Particularly. U Used. T Trade. E Education. R Research. Parts of computer There are two main parts of computer. 1. Software. 2. Hardware. Hardware The parts which has any specific or physical shape. Or the touchable parts of computer is called hardware. Types of hardware
- 3. 2 | P a g e Input hardware/device Output hardware/device Storage hardware/device Processing hardware/device Input Device/Hardware All those hardware in computer which are used for inserting data/instruction into computer system. I.e. mouse, keyboard, scanner, joystick etc. Output Device/Hardware Those devices which are given or display the result of given instruction. I.e. printer, monitor, TV, LCD, LED, speaker etc. Storage Device/Hardware Those devices which are store or save any kind of data are called storage devices. I.e. hard disk (external + internal), Memory card, Flash drive (USB) / universal serial bus. Processing Device/Hardware Those devices which work for the calculation, when you give instruction to the computer, computer process on it I.e. CPU (central processing unit) Software The set of instruction used to solve the problem of Computer user. Or Software is a collection of instructions that enable the user to interact with a computer, its hardware, or perform tasks. Without software, computers would be useless. For example, without your Internet browser, you could not surf the Internet or read this page and without an operating system, the browser could not run on your computer. The first piece of computer software? The first software program that was held in electronic memory was written by Tom Kilburn. The program calculated the highest factor of the integer 2^18 = 262,144 and was successfully executed on June 21st of 1948 at the University of Manchester. The computer that held that program was called the Small Scale Experimental Machine, otherwise known as the "Baby" computer. This "Manchester Baby" is largely celebrated as the birth of software.
- 4. 3 | P a g e Types of software System software. Application software. System software? The software which fulfill the requirements of system are called system software. Or System software is designed to operate the computer hardware, to provide basic functionality, and to provide a platform for running application software. System software includes: Operating system, an essential collection of computer programs that manages resources and provides common services for other software. I.e. operating system, DOS etc. OS (Operating system) It is a system software which is used to operate the system in a CLI or GUI mode. MS-DOS (Microsoft disk operating system). It is an operating system for x86-based personal computers mostly developed by Microsoft. Or it is a non-graphical command line operating system Or it is a system software which is used to operate the system in a CLI (Command Line Interface) Mode. Windows? It is a system software which is used to operate the system in a GUI (Graphical User Interface) Mode. Functions of an operating system. The operating system is used for performing several important functions such as data transmission. These functions are described below: Booting up and providing a user interface. The operating system also helps in the booting up process. Once the computer has been booted up, the user can work on it. An interface is a way in which two people communicate. A user interface is a program that allows a user to communicate with the computer.
- 5. 4 | P a g e Managing programs. The operating system runs all system software and application software stored on the computer. Any problem in the operating system means that neither system nor application software can run properly Managing files and directories. The operating system maintains files and folders by storing each file at a unique location in its memory. The operating system can also change the location of a file if required by the user. It also allows the same file to be used by two different application programs. Controlling system devices. The operating system controls system devices such as peripheral devices and drives. The operating system ensures that the devices perform the exact function that is needed by the user. It coordinates between the devices and application programs Multitasking. An operating system can make it easy to multitask. Multitasking1 means doing two or more things at the same time. The operating system lets users use several devices and work on several application programs at the same time. Components of an operating system. Let’s now look at the parts of an operating system that allow it to perform its functions. An operating system has many important parts. We will learn about three of them The loader. The loader is an important part of the operating system. The loader loads all programs and instructions from the backing storage to the main memory. Once the programs have been loaded, the user can start working on them. The instructions are followed by the computer to perform the tasks required by the user. The loader also activates other devices and components. Programs and instructions. The operating system contains several programs that can be run on the computer. The operating system also contains instructions that the computer can follow to run the programs. The device driver or device manager is a program that automatically runs the system devices attached to the computer. These devices area installed through drivers. The
- 6. 5 | P a g e operating system displays a list of devices and tells the user whether their drivers are updated or not. If the driver is missing, it has to be installed The user-computer interface. The user-computer interface makes it easy for users to give instructions to a computer even if they do not understand machine code. Machine code is the language understood by computers. Command Line Interface (CLI) and Graphical User Interface (GUI) are common types of interface. Usually, a CLI is faster than a GUI, but a GUI is simpler to use. DOS is an operating system based on Command Line Interface. It follows typed commands to perform required tasks. It is fast but not very interesting. Users find it difficult to learn the syntax of each and every command. Still, the command line interface is used when purely text-based data and instructions are to be used or a problem in the computer has to be corrected. Microsoft Windows is an example of an operating system based on Graphical User Interface. Instead of typing command, users can click on an icon and drag it to a desired location or folder. This makes it interesting and simpler to use. A GUI is also called a WIMP (Windows, Icons, Menus, Pointing Device) interface. It is used whenever visual data is needed. Utility programs. A program that performs a very specific task, usually related to managing system resources. Operating systems contain a number of utilities for managing disk drives, printers, and other devices. The file manager. A file manager is a software program that helps a user manage all the files on their computer. For example, all file managers allow the user to view, edit, copy, and delete the files on their computer. Tip: With recent versions of Microsoft Windows, Windows Explorer (Explorer) is considered the Default file manager.
- 7. 6 | P a g e The image viewer. An image viewer or image browser is a computer program that can display stored graphical images; it can often handle various graphics file formats. Such software usually renders the image according to properties of the display such as color depth, display resolution, and color profile.
- 8. 7 | P a g e The disk scanner. A disk scanner is a utility program that searches the hard disk for unnecessary or damaged files and suggests what to do about them. It also manages folders like Temporary Internet Files to release space for essential data. Microsoft Disk Cleanup is a common disk scanner. The disk defragmenter. Sometimes different parts of the same file might be stored at different locations in the memory of the computer. The file is said to be fragmented. A disk defragmenter moves all the fragments of the file to a single location.
- 9. 8 | P a g e The virus scanner. Computer software used to prevent, detect and remove malicious software. A virus is a program that destroys files stored on the computers. A virus scanner is a utility program that scans the system for viruses and deletes them before they can cause any more damage.
- 10. 9 | P a g e Backup software. Backup software are computer programs used to perform backup; they create supplementary exact copies of files, databases or entire computers. These programs may later use the supplementary copies to restore the original contents in the event of data loss. Software development tools A programming tool or software development tool is a computer program that software developers use to create, debug, maintain, or otherwise support other programs and applications. Compiler. A compiler is a computer program (or a set of programs) that transforms source code written in a programming language (the source language) into another computer language (the target language), with the latter often having a binary form known as object code. Linker In computing, a linker or link editor is a computer program that takes one or more object files generated by a compiler and combines them into a single executable file, library file, or another object file.
- 11. 10 | P a g e Debugger A computer program that assists in the detection and correction of errors in computer programs. The process of removing errors from a file is called debugging. Applications Software The software which can fulfill the requirements of user is called application software.
- 12. 11 | P a g e Or Application software, or simply applications, are often called productivity programs or end- user programs because they enable the user to complete tasks such as creating documents, spreadsheets, databases, and publications, doing online research, sending email, designing graphics, running businesses, and even playing games! Or Application software is used to perform dedicated tasks. I.e. Microsoft office, Cisco Packet tracer, GNS3, Corel draw etc. Different Types of Application Software Word Processing Software it is used for documentation purpose. This software enables users to create and edit documents. The most popular examples of this type of software are MS-Word, WordPad and Notepad among other text editors. Database Software a database is a collection of organized data. Database is a structured collection of data. A computer database relies on database software to organize data and enable database users to perform database operations. Database software allows users to store and retrieve data from databases. Examples are Oracle, MS Access, etc.
- 13. 12 | P a g e Spreadsheet Software Excel, Lotus 1-2-3 and Apple Numbers are some examples of spreadsheet software. These software allow users to perform calculations using spreadsheets. They simulate paper worksheets by displaying multiple cells that make a grid. Multimedia Software they allow users to create and play audio and video files. They are capable of playing media files. Audio converters, audio players, burners, video encoders and decoders are some forms of multimedia software. Examples of this type include Real Player and Media Player. Presentation Software The software that is used to display information in the form of a slide show is known as
- 14. 13 | P a g e presentation software. This type of software includes three functions, namely, editing that allows insertion and formatting of text, methods to include graphics in the text and a functionality of executing slide shows. Microsoft PowerPoint is the best example of presentation software. Enterprise Software it deals with the needs of organizational processes and data flow. Customer relationship management or the financial processes in an organization are carried out with the help of enterprise software. Enterprise software, also known as enterprise application software (EAS), is computer software used to satisfy the needs of an organization rather than individual users. Such organizations would include businesses, schools, interest-based user groups, clubs, charities, or governments Information Worker Software Individual projects within a department and with individual needs of creation and management of information are handled by information worker software. Documentation tools, resource management tools and personal management systems fall under this category of application software. Productivity software Productivity software helps people create new designs for products. Productivity software also helps to manufacture products in less time and with less effort.
- 15. 14 | P a g e Computer-Aided Design (CAD), Computer-Aided Manufacturing (CAM), and Computer-Aided Engineering (CAE) are three types of productivity software. Decision making software Decision-making software is an advanced type of software that is used by business. It helps managers to make decisions by processing very large amounts of data stored in a database. Decision Support System (DSSs) and Expert Systems (ESs) are common types of decision- making software. Educational software Educational software is dedicated to learning and instruction. Educational software can be used to provide learning materials, examples, and tests on different topics. Reference software consists of dictionaries and encyclopedias. It has the capabilities of running tests and tracking progress. It also has the capabilities of a collaborative software. It is often used in teaching and self-learning. Dictionaries like Britannica and Encarta, mathematical software like Google Earth and NASA World Wind are some of the well-known names in this category.
- 16. 15 | P a g e Content Access Software it is used to access content without editing. Common examples of content access software are web browsers and media players. Application Suites an application suite is an important type of application software. It consists of a group of applications combined to perform related functions. Open Office and Microsoft Office are the best examples of this type of application software. These application suites, as you know, come as bundles of applications like word processors, spreadsheets, presentation software, etc. Applications in the suite can work together or operate on each other's files.
- 17. 16 | P a g e Graphic software. A program or collection of programs that enable a person to manipulate images or models visually on a computer. Adobe Photoshop is the most used graphic software. Simulation Software Used to simulate physical or abstract systems, simulation software finds applications in both, research and entertainment. Flight simulators and scientific simulators are examples of simulation software.