Computer software consists of application software and system software. Application software includes programs like word processing software, database software, spreadsheet software, and presentation software. On the other hand, system software controls the computer hardware and includes operating systems like Microsoft Windows, Mac OS, and Linux, as well as utility software for analysis, configuration, optimization, and maintenance. Operating systems such as Android and Apple iOS are used for mobile devices. Computer software is essential for computer functionality and is categorized into application and system software.