What This Chapter Covers

A computer is an electronic machine that accepts data, processes it according to a set of instructions, stores the data and results, and gives out useful information — quickly, accurately, and automatically. It has become the single most important tool of modern business, education, government, and daily life. Before we can learn to use a computer or to program one, we need to understand what a computer system is actually made of and how its parts fit together.

This chapter — the opening chapter of the Information Technology elective in the Odisha CHSE +2 First-Year Commerce course — builds that foundation in two parts. The first part looks at the hardware of a computer: the way a computer is organised into functional units, the central processing unit (CPU) that does the actual work, the memory that holds data and instructions, the input and output devices through which we communicate with the machine, and the buses and ports that connect everything together. The second part looks at the software: the sets of instructions that tell the hardware what to do, grouped into system software, utility software, and application software, and the modern idea of open-source software.

The computer-science ideas taught here are the standard, well-established principles of computing that are followed everywhere; this is a state-specific IT elective built on those same principles, written in our own words, and is not a reproduction of any particular publisher's textbook.

The chapter is organised as follows: the computer system and its organisation (Section a), the central processing unit (Section b), the memory unit (Section c), input devices (Section d), output devices (Section e), the communication bus and ports (Section f), and the types of software including open-source (Section g).