Types of Computers

Desktop

The desktop is a personal computer (PC) in a form intended for regular use at a single location. They come in a variety of types ranging from large vertical tower cases to small form factor models that can be tucked behind an LCD monitor. Most of these computers have separate screens and keyboards.

Mainframe

Mainframes are powerful computers used mainly by large organisations for critical applications, typically bulk data processing such as census, industry and consumer statistics, enterprise resource planning and financial transaction processing.

Laptop

is a personal computer designed for mobile use that is small and light enough for one person to rest on their lap. A laptop integrates most of the typical components of a desktop computer, including a display a keyboard, a pointing device (a touchpad) and speakers into a single unit. A laptop is powered by mains electricity via an AC adapter, and can be used away from an outlet using a rechargeable battery.

Tablet

is a laptop PC equipped with a stylus (a small pen-shaped instument that is used to input commands to a computer screen, mobile device or graphics tablet) or a touchscreen. This form facot is intended to offer a more mobile PC; this PCs may be used where notebooks are impractical or unwieldy, or do not provide the needed functionality.

Netbook

A Netbook (sometimes also called mini notebooks or ultraportables) are a branch of subnotebooks, a rapidly evolving category of small, lightweight and inexpensive laptop computers suited for general computing and accessing Web-based applications; they are often marketed as “companion devices”, i.e. to augment a user’s other computer access.

Handheld-PC

is a term for a computer built around a form factor which is smaller than any standard laptop computer. It is sometimes referred to as a Palmtop.

Hierarchy of computer parts

graph TD id1[Computer System] id2[programms and data - software] id3[mechanical and electronic equipment - hardware] id4[the brain of the computer - CPU] id5[main memory] id6[RAM] id7[ROM] id8[physical units attached to the computer - peripherals] id9[input/ouptut devices] id10[Keyboard] id11[Mouse] id12[Monitor] id13[Printer] id14[storage devices] id15[Optical devices] id16[Floppy] id17[Hard drives] id18[CD] id19[DVD] id1 --> id2 id1 --> id3 id3 --> id8 id8 --> id9 id9 --> id10 id9 --> id11 id9 --> id12 id9 --> id13 id8 --> id14 id14 --> id15 id15 --> id18 id15 --> id19 id14 --> id16 id14 --> id17 id5 --> id6 id5 --> id7 id3 --> id5 id3 --> id4