SOFTWARE

Types of Software Application Software System Software

Application Software Performs specific tasks and works on top of the operating system. Three main types General Purpose Special Purpose Custom Written APPLICATION SOFTWARE OPERATING SYSTEM

General Purpose Software that performs basic tasks that most users would need to do. Comes in a software suite or Integrated software. Eg. Microsoft Office, PDF reader, Adobe Photoshop ADVANTAGES DISADVANTAGES Relatively Cheap Little or no Customization Easy to learn Comes in a package and cannot be separated No compatibility issues Easy to Install

Special Purpose Software designed to perform a specific task. Eg. Accounting, Engineering Design, Music player. ADVANTAGES DISADVANTAGES Meets a specific need Can be expensive Usually integrates with other software well Has no other use other than what it was made for.

Custom Written Software Software that is designed specifically for an organization to meet their individual needs. Eg. Government databases, Large businesses. ADVANTAGES DISADVANTAGES Meets the individual needs of the user Very costly Can be modified to meet new needs Difficult to troubleshoot at times Cannot be used for anything else.

System software

System Software They enable the computer to run properly. Application programs depend on the System software to run. There are 2 main types OS (Operating System) Utilities

Operating Systems (OS) The operating system is the set of programs that controls all the hardware and application programs that make up the computer system. They are the most important programs because every other program depends on it. Eg. PC-Windows, Linux, UNIX, Mac OS, DOS Phone -Android, iOS, Symbian, Windows Mobile

The OS does many functions Process Management Allotting adequate time and resources to each process/program File Management Provides the ability to modify files and folders while keeping track of their physical location on the hard drive. Memory Management Manages the memory the computer has so that every program can get to load as quickly and efficiently as possible.

OS functions contd… Input/Output Management Security and Maintenance Controls the communication with external hardware like keyboard, mouse, printers, monitor etc… Security and Maintenance Provides some level of security to ensure the software is safe from viruses and malware. Provides utilities to ensure backups and error corrections take place. User Interface Provides a user interface that the user can interact with to give inputs.

USER INTERFACES

User Interfaces THREE TYPES Command Line Menu Driven Graphical User Interface (GUI)

Command Driven Interface A user interface that requires the user to put in special commands line by line to do tasks. Eg. MS-DOS, UNIX DISADVANTAGES Requires knowledge of the commands ADVANTAGES Tasks can be executed very quickly once the commands are known.

Menu Driven Interface Interface where the user can select multiple commands from one or more menus Eg. Turbo Pascal DISADVANTAGES A lot of options may lead to confusion Some options may not be available ADVANTAGES User does not have to remember commands

Graphical User Interface (GUI) Interface where images are used to represent the choices a user can make. Eg. Windows, Linux, MacOS, iOS, Android ADVANTAGES Easy to understand and learn DISADVANTAGES Some tasks can take long because there are many menus to go through to get to one choice

Multitasking, Multiprocessing, Multiprogramming The execution of two tasks at the same time. MULTIPROCESSING The use of 2 or more CPU’s to execute different tasks simultaneously MULTIPROGRAMMING When two or more programs run on the same processor working one after the other.

PROCESSING

Processing TYPES OF PROCESSING Batch Processing Online Processing Real Time Processing

Batch Processing When Data is collected and stored for a period of time and processed after. Also known as offline processing. Eg. Salaries in a company, Printing documents, Birth Certificates

Online Processing When data is collected and processed immediately and cannot be changed. Eg. ATM Machines, Flight Bookings, Online reservations

Real-time processing When data is input processed and output continuously. Activities are constantly happening. Eg. Real time flight bookings, Facebook feeds, Checking criminal records

Comparison Table TYPE OF PROCESSING ADVANTAGES DISADVANTAGES BATCH Saves on time in the long run Changes cannot be made easily once batch has not been run. ONLINE Takes information and processes it on demand Changes are not made as quickly REAL-TIME Changes are made instantly Requires high processing power