Software PDF

SOFTWARE Dr. O. D. NINAN November, 2024 Dr. O. D. NINAN November 2024 Software Software is a set of instructions, data or programs used to operate computers and execute specific tasks. Computer software is the instructions, procedures and programs that can be executed on a computer sy...

SOFTWARE Dr. O. D. NINAN November, 2024 Dr. O. D. NINAN November 2024 Software Software is a set of instructions, data or programs used to operate computers and execute specific tasks. Computer software is the instructions, procedures and programs that can be executed on a computer system. Software gives life to hardware. Software is very essential for a computer system to function. Computer Software is broadly divided into two: 1. Systems Software (e.g. Operating Systems, Compilers, Assemblers, etc. Utility Software e. g. Anti-virus, Diagnostic software, etc.) 2. Application Software (e.g. Word-processors, Spread-sheet, Database Managers, Graphics Packages, Entertainment Software, etc.) Dr. O. D. NINAN November 2024 Systems Software System software perpetually runs in the background to maintain the basic functionalities and the hardware of the computer. They essentially acts as a mediator between the computer and the user to facilitate operations. They Communicates with computer peripheral Examples of System software are, Operating System, Device Drivers, Firmware, Utility. Operating System The Operating System is the most important systems software and it manages all the hardware resources of the computer system. Operating systems are loaded into RAM when the device starts up, and have access to the hard drive. Dr. O. D. NINAN November 2024  It manages the input, processing, output and storage operations of a computer system. It controls the entire computer components and makes sure that everything gets along well. Operating system controls the operations of a computer by communicating with end-users, managing hardware resources and files, supervising the accomplishment of tasks, and providing other support services. It comes with the computer when one buys it. Various types of operating systems, include, Android and iOS, macOS, Windows, Unix, Linux, XENIX and Ubuntu, Microsoft Disk Operating System (MS-DOS) , etc.. Dr. O. D. NINAN November 2024 Functions of Operating System Scheduling and loading of processes (Jobs) in order to provide for continuous processing. Control, selection and operation of Input/Output devices and file handling. Calling into main memory of programs as and when required. Passing of control from one program (job) to another under a system of priority when more than one application program is in main memory. Provision of error correction routines. Keeps complete record (Log) of all that happens during processing of various jobs. Communication with the computer operator and users via the visual display unit. The reading/writing records to file, and where necessary, blocking and deblocking. Peripheral control, advancing or rewinding of magnetic tape reel, advancing paper in the printer. Opening and closing files, i.e. checking file labels, etc. Dr. O. D. NINAN November 2024 Programming Languages A programming language is an artificial language designed for use by people in instructing machines. Its characteristics are a structure and syntax that prevents ambiguous constructions. It is a language in which programs are written to control the operations of the computer system. With respect to a particular computer system, a programming language is often termed a source language; a source language may either be a low-level language or a high level language. A high level language is one (e.g. COBOL, PASCAL and FORTRAN) that is designed for ease of use in writing programs and is intended to be used to program computers of different manufactures and types. The term high-level is used because a whole sequence of computer operation can be specified by writing a single instruction in the language. By contrast, a low level language is one that requires the programmer to tell the computer quite explicitly what is to be done. Dr. O. D. NINAN November 2024 High Level Languages (i) COBOL: It uses English-like statements for the writing of instructions, and is more applicable to business data processing. The name COBOL stands for COmmon Business-Oriented Languages. (ii) FORTRAN: It is an algebraic language used for preparing instructions in the form of arithmetic formula in scientific applications. The name FORTRAN is an abbreviation for FORmular TRANslation. (iii) ALGOL: This stands for ALGOrithmic Language for scientific programming using algorithms. Other examples of High Level Languages include: Pascal C Language Python Dr. O. D. NINAN November 2024 Compilers Conversion of codes written by humans into lower-level machine code is performed by compilers. They translate source code from a high-level programming language to a low-level programming language These machine codes can be interpreted directly by computer hardware. They are the basis for creating even the most complicated and sophisticated software. Eg. Java compiler, C compiler, C++ compiler…. Debuggers Debugging is the process of identifying actual and potential bugs within your code and fixing them. Debuggers play an essential role in ensuring your software or application performs well by testing and debugging the computer code. Dr. O. D. NINAN November 2024 Linkers Linkers are responsible for combining various individual files from a compiler into a single executable file. The file converted, as a result, runs on its own without requiring a programming environment. Malware Malware is software developed to attack computers and their software in a harmful way to cause them to misbehave or seize to work. This includes viruses, ransomware, trojans, and worms. Since there are a variety of malware that may be mistakenly downloaded, it is crucial to have antimalware software on your computer to keep it safe from their attacks. Dr. O. D. NINAN November 2024 Device Drivers These are software program that make possible the communication between the computer system and other peripheral devices (e.g. printer, mouse, etc.) attached to the system. They take the instructions and/or data from the computer system and converts them into a form that is readily understood by a peripheral device, and vice versa. Device drivers handle the operations of the hardware devices connected to a computer. They act as a software interface for the hardware devices such as, printers, scanners, plotters, etc. Dr. O. D. NINAN November 2024 Utility software Utility software functions to configure, maintain, and offer support in the analysis and optimization of the computer. They perform a variety of housekeeping and file conversion functions. They perform particular functions related to computer system management and maintenance. Examples are: Anti-virus software, Data compression software, Disk optimization software, Disk backup software etc. Dr. O. D. NINAN November 2024 Application Software An application software is a software type that carries out specific tasks for the specific needs of the users. They could either fall into the category of a general purpose application software or a special purpose application software. A general-purpose software can be used to perform more than a specific task, e.g., Microsft Word can be used for typesetting, spell-checking, finding and replacing contents of a document, etc. A specific purpose application software is used to accomplish specific tasks in specific domains, e.g., insurance software is used to perform functions specific to insurance. Dr. O. D. NINAN November 2024 Examples of Application software are: Payroll Software Student Record Software (eportal and ISIS) Inventory Management Software Income Tax Software Hotel Reservation Software Microsoft Office Suite Software Microsoft Word Microsoft Excel Microsoft Powerpoint Microsoft Access etc. Dr. O. D. NINAN November 2024 Custom-built Software Custom software (also known as bespoke software or tailor-made software) is software that is specially developed for some specific organization or other user. It is SW built for a particular organization to fulfill the needs of that particular organization. A common example is a system for processing students’ results in institutions. This type of SW is expensive because the builder has to recoup costs and make a profit from a single sale. The delivery time is longer. Customers get more productivity out of it because it is built according to their exact specifications – just like a custom-built shoe fits better, but generally is more expensive, and requires a longer period for delivery. Dr. O. D. NINAN November 2024  Main Types of Software Licensees 1. Proprietary – Most software on a Windows PC or a Macintosh belongs to this category 2. Freeware – Most software on a Linux PC belongs to that category 3. Shareware – the category which lies between the above two categories Proprietary Software License The user needs to pay the maker of the Software for buying a license that allows the user to make use of the software. The license, generally, does not transfer the ownership of the software to the buyer but just allows the user to make use of it. The user is legally barred from making copies of the licensed software for sales or distribution. Generally, the license is meant for personal use only. Most software in use in the world is of this type. Examples are: Windows, Mac OS, MS Word, Adobe Photoshop, Norton Antivirus etc. Dr. O. D. NINAN November 2024 Types of Proprietary Licenses Single-user license: A single user license is meant solely for the buyer and not any other person has legal right to the software. Multi-user license: A multiuser license allows more than one person legal right of usage of the software. In many cases the number of people who have the legal right of usage is specified. Concurrent-user license: The license allows software installed in the central computer to be used by more than one person at a time. Site license: The license allows a buyer to install the software from a website. Dr. O. D. NINAN November 2024 Freeware software License It is also known as “Public Domain Software”. The license allows the user free usage of the software. The author, however, generally retains the ownership of the software. It can usually be downloaded from author’s website or other Web sites. Examples are Linux; LaTeX; Netscape Web browser – the Navigator; the Internet Explorer etc. Shareware software License The license allows the user free usage of the software, but with a request that the user pay a token to the author if the user is satisfied with the software. The author retains ownership of the software. It is often downloaded from author’s Web sites. Examples are: WinZip, Download Accelerator. The author is an individual or a small business that cannot afford to advertise. No one will even try the software if it had a price. The expectation is that the user will try the software for free, find it useful, and then pay the very small price for the software Dr. O. D. NINAN November 2024 Trialware License This licence is similar to shareware, but different in the following areas: The software is usable for a short period only. After an initial trial period that can range from a week to a few months, the software self-destructs. Can be downloaded from the Internet or alternatively, the user can receive a copy by writing to the maker of the software. Trialware are good so customers can have a risk-free trial though for a limited-period only. Dr. O. D. NINAN November 2024 Firmware Firmware is a set of instructions or programs written in machine language and designed to act as intermediary between the software and hardware. Is a software that provides basic machine instructions that allow the hardware to function and communicate with other software running on a device. Firmware is embedded in the read-only memory of a system and is a type of permanent software that offers low-level control for certain device hardware. It is semi permanently stored in the hardware and updated less often. Firmware is found in a range of computing devices, and those not considered computing devices. Examples, Basic Input Output System (BIOS), Extensible Firmware Interface (EFI), Embeded systems (Keyboard, TV, Remote, Graphic cards, Printers, etc.) Dr. O. D. NINAN November 2024