CLASSIFICATION OF COMPUTER
📊 Types of Computers — Quick Reference Table
|
Type |
Description |
Examples |
|
Supercomputer |
Extremely
fast, handles complex calculations. |
Weather
forecasting, scientific research (e.g., Fugaku, IBM Summit) |
|
Mainframe |
Large,
powerful, supports many users at once. |
Banking,
airline systems (e.g., IBM z16) |
|
Minicomputer |
Mid-sized,
used in small to medium businesses. |
Manufacturing
control, business databases |
|
Microcomputer |
Designed
for personal use. |
Desktops,
laptops, tablets, smartphones |
|
Analog
Computer |
Works
with continuous data (physical quantities). |
Speedometers,
old thermometers |
|
Digital
Computer |
Uses
binary data (0s and 1s). |
PCs,
calculators, digital watches |
|
Hybrid
Computer |
Combines
analog and digital capabilities. |
Hospital
monitoring devices, fuel pumps |
|
Desktop
Computer |
Fixed,
powerful, often upgradable. |
Office
PCs, gaming desktops |
|
Laptop
Computer |
Portable,
battery-powered. |
MacBook,
Dell XPS, HP Pavilion |
|
Tablet
Computer |
Touchscreen,
lightweight. |
iPad,
Samsung Galaxy Tab |
|
Smartphone |
Compact,
combines phone and computing features. |
iPhone,
Samsung Galaxy, OneP |
The digital computers that are available nowadays vary in
their sized and types.
The computers are broadly classified into four categories based
on their size and type
- Microcomputers
- Minicomputer
- Mainframe
computers
- Supercomputer
Microcomputers
- Microcomputers
are small, low-cost and single-user digital computer.
- They
consist of CPU, input unit, output unit, storage unit and the software.
- Although
microcomputers are stand-alone machines, they can be connected together to
create a network of computers that can serve more than one user.
- IBM
PC based on Pentium microprocessor and Apple Macintosh are some examples
of microcomputers.
- Microcomputers
include desktop computers, notebook computers or laptop, tablet computer,
handheld computer, smart phones and net book.
i. Desktop Computer or Personal Computer (PC) is the
most common type of microcomputer.
- It is
a stand-alone machine that can be placed on the desk.
- Externally,
it consists of three units-keyboards, monitor, and a system unit
containing the CPU, memory, hard disk drive, etc.
- It is
not very expensive and is suited to the needs of a single user at home,
small business units, and organizations.
- Apple,
Microsoft, HP, Dell and Lenovo are some of the PC manufactures.
ii. Notebook Computers or Laptop resembles a
notebook.
- They
are portable and have all the features of a desktop computer.
- The
advantage of the laptop is that it is small in size (can be put inside a
briefcase), can be carried anywhere, has a battery backup and has all the
functionality of the desktop.
- Laptops
can be placed on the lap while working (hence the name).
- Laptops
are costlier than the desktop machines.
iii. Notebook These are smaller notebooks optimized
for low weight and low cost, and are designed for accessing web-based
applications.
- Starting
with the earliest notebook in late 2007, they have gained significant
popularity now.
- Notebooks
deliver the performance needed to enjoy popular activities like streaming
videos or music, emailing, Web surfing or instant messaging.
- The
word notebook was created as a blend of Internet and notebook.
iv. Tablet Computer has features of the notebook but
it can accept input from a stylus or a pen instead of the keyboard or mouse, it
is a portable computer. Tablet computer are the new kind of PCs.
v. Handheld Computer or Personal Digital Assistant (PDA)
is a small computer that can be held on the top of the palm.
- It is
small in size.
- Instead
of the keyboard, PDA uses a pen or a stylus for input.
- Connected
to the Internet via a wireless connection.
- Casio
and Apple are some of the manufacturers of PDA.
- Over
the last few years, PDAs have merged into mobile phones to create smart
phones.
vi. Smart Phones are cellular phones that function
both as a phone and as a small PC.
- They
may use a stylus or a pen, or may have a small keyboard.
- They
can be connected to the Internet wirelessly.
- They
are used to access the electronic-mail, download music, play games, etc.
- Blackberry,
Apple, HTC, Nokia and LG are some of the manufacturers of smart phones.
Minicomputers
Minicomputers are digital computers, generally used
in multi-user systems.
- They
have high processing speed and high storage capacity than the
microcomputers.
- Minicomputers
can support 4-200 users simultaneously.
- The
users can access the minicomputer through their PCs or terminal.
- They
are used for real-time applications in industries, research centers, etc.
- PDA
11, IBM (8000 series) are some of the widely used minicomputers.
Mainframe Computer
- Mainframe
computers (Figure 1.14) are multi-user, multi-programming and high
performance computers.
- They
operate at a very high speed, have very large storage capacity and can
handle the workload of many users.
- Mainframe
computers are large and powerful systems generally used in centralized
databases.
- The
user accesses the mainframe computer via a terminal that may be a dumb
terminal, an intelligent terminal or a PC.
- A
dumb terminal cannot store data or do processing of its own.
It has the input and output device only. - An
intelligent terminal has the input and output device, can do processing,
but cannot store data of its own.
- The
dumb and the intelligent terminal use the processing power and the
storage facility of the mainframe computer.
- Mainframe
computers are used in organization like banks or companies, where many
people require frequent access to the same data.
- Some
examples of mainframes are CDC 6600 and IBM ES000 series.
Supercomputers
- Supercomputers
(Figure 1.15) are the fastest and the most expensive machines.
- They
have high processing speed compared to other computers.
- The
speed of a supercomputer is generally measured in FLOPS (Floating point
Operations per Second).
- Some
of the faster supercomputers can perform trillions of calculations per
second.
- Supercomputers
are built by interconnecting thousands of processors that can work in
parallel.
- Supercomputers
are used for highly calculation-intensive tasks, such as weather
forecasting, climate research (global warming), molecular research,
biological research, nuclear research and aircraft design.
- They
are also used in major universities, military agencies and scientific
research laboratories.
- Some
examples of supercomputers are IBM Roadrunner, IBM Blue gene and Intel
ASCI red.
On the basis of Work
- Digital
Computer
- Analog
Computer
- Hybrid
Computer
1. Digital computer uses distinct values to represent the data internally.
- All
information is represented using the digits 0’s and 1’s.
- The
computers that we use at our homes and offices are digital computers.
- Digital
signal represents particular state that is: 0 (low) or 1 (high), YES or
NO, ON or OFF, TRUE OR FALSE.
- These
systems store and process the data in digital form (strings of 0's and
1's)
- They
are capable of processing analog signals but the analog signals have to be
converted into digital signals using an ADC before feeding into the
digital computers.
2. Analog computer is another kind of a computer that represents data as variable across a continuous range of values.
- The
earliest computers were analog computers.
- Analog
computers are used for measuring of parameters that vary continuously in
real time, such as temperature, pressure and voltage.
- Analog
computers may be more flexible but generally less precise than digital
computers.
- These
computers represent data in the form of continuous electrical signals and
uses physical quantity like, electric current, voltage, temperature and
pressure of a motor system.
- Based
on analog mechanism.
- An
analog computer is the one that measures physical values such as:
temperature, pressure, and speedometer, thermometer, multi-meter etc.
- These
are fast and multi-tasked.
- Results
displayed by these computers are less accurate.
- Analogue
computers are used in hospital to measure the size of stone in kidney and
mental disease diagnostics (CT scan with photos).
- Powerful
in solving differential equations.
- These
computers use OP-AMP (Operational Amplifier).
- Examples:
Seismograph.
3. Hybrid computer (digital + analog)
- These
computers are a combination of both digital and analog computers.
- Hybrid
computers are computers that exhibit features of analog computers
and digital computers.
- The
digital component normally serves as the controller and provides logical
operations, while the analog component normally serves as a solver of
differential equations.
- The
hybrid computers can transfer data from analog to digital and digital to
analog.
- Used
in industrial process control, jet plans, airplanes
On the basis of Brand
- IBM
PC
- IBM
Compatible
- Apple/Macintosh
i. IBM PC
IBM PC is a microcomputer produced by IBM Company. Dr. Herman Horierth
established IBM in 1923. It is leading the market of mainframe and PC's. It
used the processors, multimedia devices and some other hardware's parts,
developed by some other companies like Intel. But use the principal of its own.
So all the computer developed by IBM Company is called IBM Computer.
ii. IBM Compatible
IBM compatible can use hardware and software designed for IBM PC. The internal
architecture of IBM compatible is similar to IBM PC. So they are called
duplicate computers.
Example Epson, Acer etc.
iii. Apple/Macintosh
Apple Corporation was established in 1970 in USA. Its computer
are called Apple/Macintosh (Mac) computer. The internal architecture of these
computers is totally different form that of IBM. Therefore they need their own
software.
On the basic of Model
- XT
computer
- AT
computer
- PS/2
computer
i. XT computer:
XT (Extra Technology) computer are old technology computers with much slower
processing speed (not more than 4.77 MHZ)
Advance GUI based software like windows cannot be run in these computers.
Everything