Applications are the tools employed by users. Application software programs (such as Microsoft Word, Access, Excel, and so forth) use the operating-system software enabling users to create, manipulate, and present data. This tutorial focuses on the earlier operating-system software?MS-DOS and Windows 3.x. Although MS-DOS and Windows 3.x are somewhat outdated, they remain the foundation from which the newer 32-bit operating systems like Windows 95, Windows 98, and Windows 2000 evolved. Many fundamental concepts and conventions used with today's operating systems stem from these beginnings. As an A+ technician aspirant, you will find some questions regarding MS-DOS and Windows 3.x on the exam.
The term software refers to any program (set of instructions) that directs a computer to carry out a task or function. Software can be divided into two categories: operating systems and applications. Operating-system software is used to manage hardware, data, and application software. No computer can run without an operating system. MS-DOS, Windows 3.x, Windows 95, Windows 98, Windows NT, Windows 2000, OS/2, and UNIX are examples of operating systems.