Introduction to Computer
Introduction to Computer is the CCC domain that tests how well you understand the machine itself: hardware, software, data, storage and the input–process–output cycle. Questions often ask you to classify a device or choose the correct unit, so learn the categories rather than memorising brand names.
Core rules
- A computer follows input → process → output; storage holds data and instructions for later use. Data becomes information after processing.
- Hardware is physical; software is a set of instructions. System software includes the operating system; application software includes Word, Excel and browsers.
- Primary memory (RAM, ROM, cache) is directly accessed by the CPU. RAM is volatile; ROM is non-volatile.
- Secondary storage (HDD, SSD, pen drive, DVD) is non-volatile and usually slower and larger.
- Units: 8 bits = 1 byte; 1024 bytes = 1 KB; 1024 KB = 1 MB; 1024 MB = 1 GB; 1024 GB = 1 TB.
- Input devices send data in (keyboard, mouse, scanner, microphone); output devices send results out (monitor, printer, speaker). A touchscreen is both.
Worked example
A candidate says, “A 16 GB pen drive is better primary memory than 8 GB RAM because 16 is bigger.” The reasoning is wrong on role, not size. RAM is primary memory read directly by the CPU; a pen drive is secondary storage. A larger pen drive gives more file space, but it does not replace RAM. The correct comparison is capacity within the same category, not capacity across categories.
Traps
Do not call ROM volatile; do not confuse a byte with a bit; do not label a scanner as output; and do not treat firmware as application software. Read “primary” and “secondary” carefully before choosing.