A mobile devices is a computing device designed to hold in the hand. Mobile devices typically have small screens and some of them have keywords. Mobile devices usually have no disk drivers. The programs and data are permanently stored on special memory or on a small storage media such as smart card. Mobile devices can be connected to large network to exchange data. Mobile devices are almost always powered by a rechargeable battery system. It has build-in wireless connectivity for Internet access. Popular types of mobile devices are smart phones, handheld computer, portable media players and e-book.
A smartphones is a cell phone that includes many features of computer and can run general purpose computing applications. Many smartphones have touch screens to input data using fingertip or a stylus. Some have a build-in mini keyboard. iPhone is an example of smartphone.
Some features of smartphones are as follows:
- Internet access
- Make and answer phone cells
- Send text messages, picture messages and video messages
- Personal information management such as calendar address book and calculator etc.
- Send and receive email messages
- Communicate wirelessly with other devices or computers
- Build-in camera to share images or video with others
- Conduct live video calls
- Play and organize music
- Voice recording
- GPS services
- Computing power to run programs like word processors etc.
2. Handheld Computer
A handheld computer is a small, Lightweight computer that easily fits in the hand. Many handheld computers communicate wirelessly with other devices or computers. Some have small keyboards and others have a touch screen and also include a stylus for input. Many handheld computers are used by mobile employees to take inventory and check supplies etc.
Handheld computer is not very powerful and cannot perform many tasks that can be performed by desktop and notebook computer.
3. Portable Media Player
A Portable media player is a mobile device designed to store, organize and play digital media. Digital media includes music, photos and videos. These devices offer camera, access to the internet and variety of applications.
Some portable media player models have touch screen or a touch-sensitive pad. A touch-sensitive pad contains buttons and wheels to be used with a thumb or finger. It can be used to scroll, play music, view photos, watch videos and adjust volume etc. Portable media players usually include a set of earbuds that are small speakers that rest inside each ear canal. iPod Touch is an example of portable media player.
4. E-Book Reader
E-Book reader is designed for reading books, magazines and other digital publications. It is also called e-reader. An e-book is an electronic version of a printed book readable on computers and other mobile devices. E-reader device can hold thousands of e-books.
Most e-reader have a touch screen and have build-in wireless technology to connect to the internet. An on-screen keyboard can be used to navigate, search, and highlight the contents. The user can browse an electronic bookstore and download new eBooks quickly via wireless connection.
Some e-reader use e-link technology. It makes screens easy to read and extends battery life for up to two months. The reader can feel the experience of reading a printed book. The screen can easily to read even in bright sunlight. Some e-reader have LCD screens similar to laptops and tablets.
LCD screens can display colors and are used to view magazines and books with colorful photos. However, it is more difficult to read contents in bright sunlight.
Minicomputer is typically larger, more powerful and more expensive than personal computer. Minicomputer can serve up to several hundreds connected users at the same time. It can be used in networked environment as server computer It is also called mid-range server. It is normally accessed by users through a personal computer, thin client or a dumb terminal. A device with a monitor and keyboard is called dumb terminal.
Minicomputers are used by small and medium-sized organizations. They provide centralized store of information and computer programs.
Some examples of minicomputers are as follows:
- Prime 9955
- HP 3000
- AS 400
- VAX 8600
6. Mainframe Computers
Mainframe computer is a large computer designed to serve several thousands connected users at the same time. It is more powerful and expensive than minicomputer. These computers can store large amount of data, information and programs. The users access a mainframe computer through personal computer, thin client or dumb terminal. Mainframe computer is also called as enterprise server or high-ended server.
The price of mainframe computer can be several thousand dollars to several million dollars. IBM, Sun and Unisys are leading manufacturers of mainframe computers.
Mainframe computers are used in large organizations to manage large amounts of centralized data such as banks, universities, insurance companies and government departments. For example, airlines use them to maintain flight schedules, ticket reservation system etc. Govt. department such as NADRA use mainframe computers to maintain the information of population. Many shopping chains interconnect their stores with mainframe computer to track transactions immediately and maintain stock.
Some examples of mainframe computer are as follows:
- IBM S-390
- NEC 610
- DEC 10
- IBM System Z10
Supercomputer is the fastest and the most powerful computer. It is the biggest in size and more expensive than any other computer. It is used to perform complex tasks. It has a very large storage capacity and can store several thousand times more data than an average desktop computer. I also consumes so much energy. The modern supercomputer consist of thousands of microprocessor. It can process trillions of instructions in one second. The cost of one supercomputer can be up to several billion dollars.
Supercomputer is mostly used for weather forecasting, weapon design and atomic research etc. Supercomputer is also used in business and industry field. Aircraft manufacturers use it to stimulate aircraft and check its performance. Governments use super computers for different calculations and heavy jobs. Many Hollywood movies use it for animation purposes.
Examples of supercomputer areas follows:
- Blue Gene
- Deep Blue
- ASCI White
8. Embedded Computer
An embedded computer is designed for special purpose. It works as a component in a larger product. These computers are very small and have limited hardware. They perform various functions according to the requirements of the product in which they embedded.
Embedded computers are used in commonly used product such as:
- Electronics: PDAs, mobiles, video recorders and DVD players etc.
- Home Devices: Security monitoring system & programmable microwave ovens etc.
- Automobiles: Car engine controller, airbag controller etc.
- Process Controllers and Robotics: Machine controllers, blood pressure monitors etc.
Difference between Desktop and Laptop Computer
The difference between desktop and laptop computer is as follows:
|Desktop Computer||Laptop Computer|
|1. Desktop computer is not portable.||1. Laptop computer is portable.|
|2. It can be upgraded and repaired relatively easily.||2. It is relatively difficult to upgrade and repair it.|
|3. It uses more power than laptop.||3. It uses less power than desktop.|
|4. It has no batteries and cannot be used without continuous power supply.||4. It has batteries and can be used without continuous power supply.|
|5. It is generally less expensive than laptop computer.||5. It is generally more expensive than desktop.|
|6. It is typically used in offices as well as at home for personal use.||6. It is typically used at home for personal use.|
|7. It normally requires external devices like keyboard and mouse etc.||7. It has all required components like keyboard and mouse in single unit.|
|8. It is heavier than laptop computer.||8. It is light-weighted than desktop computer.|
|9. It typically does not have build-in wireless communication facility.||9. It is typically has build-in wireless communication facility.|
Difference between Laptop and Tablet
The difference between laptop and tablet is as follows:
|1. Laptop is more powerful than tablet.||1. Tablet is less powerful than laptop.|
|2. Its hardware can be upgraded.||2. Its hardware cannot be upgraded.|
|3. It has more storage capacity.||3. It has limited storage capacity.|
|4. Its size is bigger than tablet.||4. Its size is smaller than laptop.|
|5. It is thicker and heavier than tablet.||5. It is thinner and lightweight than laptop.|
|6. The user can connect more external device with laptop.||6. The user can connect a few external devices with tablet.|
|7. It does not support the applications specifically designed for tablet.||7. It does not support the applications specifically designed for laptop.|
|8. It has less battery life than tablet.||8. It has longer battery life than laptop.|
|9. It uses traditional operating system such as Windows and Mac OS etc.||9. It uses mobile operating system such as Android and iOS etc.|
|10. It normally accepts input using physical keyboard.||10. It normally accepts input using virtual keyboard with touch screen.|
Difference among Micro, Mini & Mainframe Computers
The difference among micro, mini & Mainframe computer is as follows:
|1.||Its speed is less than mini and mainframe computer.||Its speed to more than microcomputer and less than mainframe computer.||Its speed is more than micro and minicomputer.|
|2.||It can normally be used by 1 user at a time.||It can serve several hundred users at a time.||It can serve several thousand users at a time.|
|3.||Its size is small.||Its size is bigger than microcomputer.||Its size is bigger than micro and mini computer.|
|4.||Its price is several hundred to several thousand dollars.||Its price is several thousand to million dollars.||Its price is several thousand to several million dollars.|
|5.||It is used at home, offices and educational institutes.||It is used by small and medium organizations.||It is used by large organizations like banks.|