Computer Basics
Learn what a computer is, how it works, and the key components that make up every computing device.
What is a Computer?
A computer is an electronic device that processes data according to a set of instructions called a program. Computers can perform billions of calculations per second, store enormous amounts of information, and communicate across the globe instantly.
Key Components
- CPU (Central Processing Unit) — The "brain" of the computer. It fetches, decodes, and executes instructions.
- RAM (Random Access Memory) — Fast, temporary memory used while the computer is running. Data is lost when powered off.
- Storage (HDD / SSD) — Permanent data storage. SSDs are faster; HDDs are cheaper per gigabyte.
- Motherboard — The main circuit board connecting all components together.
- GPU (Graphics Processing Unit) — Handles rendering images, video, and increasingly AI workloads.
- Power Supply Unit (PSU) — Converts AC power from the wall to DC power for components.
Hardware vs Software
Hardware refers to the physical parts of a computer — things you can touch like the keyboard, screen, and chips. Software refers to programs and operating systems — the instructions that tell hardware what to do.
Think of hardware as the body and software as the mind — neither is useful without the other.
Types of Computers
- Personal Computers (PCs) — Desktop and laptop machines for everyday use.
- Servers — Powerful machines that serve data and services over a network.
- Embedded Systems — Computers inside appliances, cars, and devices (e.g., your microwave).
- Supercomputers — Massively parallel machines used for scientific research and simulations.
- Smartphones & Tablets — Pocket-sized computers with touchscreens and wireless connectivity.
How Data is Measured
- Bit — The smallest unit of data (0 or 1).
- Byte — 8 bits. Enough to store one character.
- Kilobyte (KB) — 1,024 bytes.
- Megabyte (MB) — 1,024 KB.
- Gigabyte (GB) — 1,024 MB. Typical file/app sizes.
- Terabyte (TB) — 1,024 GB. Common hard drive sizes.
What's Next?
Now that you understand the basics, explore Operating Systems to learn how software manages all this hardware, or dive into Data Structures to understand how programs organize information.