What is a computer?

Much like a calculator, a computer performs mathematical operations within a fraction of a second. So, how is a computer different from a calculator? A computer is a device that can be programmed to carry out various tasks. A computer is different from other machines, like calculators, because it can be programmed to solve complex problems as opposed to performing fixed mathematical tasks.

The components of a computer

A computer system is comprised of three key components:

   Central processing unit (CPU)

   Memory

   Input and output devices (I/O devices)

Central processing unit (CPU)

The CPU, which can be thought of as the brain of the computer, processes and executes instructions. The CPU consists of the following:

Control unit

After fetching instructions from the RAM, the control unit directs other components of the CPU on how to respond to the instructions.

Arithmetic logic unit (ALU)

The ALU performs mathematical operations, like addition and subtraction, and logical operations, like AND.

Registers

Registers are small storage units that store data temporarily. Data stored in the registers can be accessed fairly quickly by the CPU. Some common registers include rax, rbx, and rcx.

Memory

The computer stores data in memory. There are two types of memory:

Types of memory

Primary memory

Primary memory includes Random Access Memory (RAM) and Read-Only Memory (ROM). The data in primary memory can be accessed relatively faster than that in secondary memory.

Secondary memory

Secondary memory includes mass storage devices like hard disks and flash drives.

Mass storage devices

A computer uses I/O devices to interact with the users.

Input devices

Standard input devices include a mouse, a touchpad, and a keyboard. Users control the cursor on the screen using the mouse or touchpad and enter text using the keyboard.

Output devices

Typical output devices include a printer and a display screen. Users can get a hard-copy of the output from a printer and can view the output from the computer on the display screen.

Common I/O devices

Some devices fall under the category of both input and output devices. A touch screen is one such device.