CPU

Description

A Central Processing Unit (CPU), or sometimes just called processor, is a description of a class of logic machines that can execute computer programs. This broad definition can easily be applied to many early computers that existed long before the term "CPU" ever came into widespread usage. However, the term itself and its initialism have been in use in the computer industry at least since the early 1960s (Weik 1961). The form, design and implementation of CPUs have changed dramatically since the earliest examples, but their fundamental operation has remained much the same.

DDR SDRAM

DDR SDRAM (double data rate synchronous dynamic random access memory) is a class of memory integrated circuit used in computers. It achieves nearly twice the bandwidth of the preceding [single data rate] SDRAM by double pumping (transferring data on the rising and falling edges of the clock signal) without increasing the clock frequency.

Motherboard

Description

The main printed circuit board in a computer that carries the system buses. It is equipped with sockets to which all processors, memory modules, plug-in cards, daughterboards, or peripheral devices are connected.

There are primarily two types of motherboards, AT motherboard, and ATX motherboard. AT motherboards are older, and not commonly used now a days. The AT and ATX motherboards differ in the form factor. Full AT is 12" wide x 13.8" deep, and Baby AT is 8.57" wide x 13.04" deep. Full-ATX is 12" wide x 9.6" deep and Mini-ATX is 11.2" wide x 8.2" deep. Other major differences include power supply connector, and keyboard connector. AT has 5-pin large keyboard connector, where as ATX has 6-pin mini connector. Similarly, AT has single row two connectors +/-5V, and +/-12V, whereas ATX motherboard has double row single connector providing +/-5V, +/-12V, and +3.3V.


Source: Wikipedia.com, simulationexams.com

Computer Hardware

Description

A personal computer (PC) is a computer whose original sales price, size, and capabilities make it useful for individuals, intended to be operated directly by an end user, with no intervening computer operator.

Today a PC may be a desktop computer, a laptop computer or a tablet computer. The most common operating systems are Microsoft Windows and Mac OS, while the most common microprocessors are the x86 and PowerPC CPUs. Software applications for personal computers include word processing, spreadsheets, games, and a myriad of personal productivity and special-purpose software. Modern personal computers often have high-speed or dial-up connections to the Internet, allowing access to the World Wide Web and a wide range of other resources.

A PC may be a home computer, or may be found in an office, often connected to a local area network. The distinguishing characteristics are that the computer is primarily used, interactively, by one person at a time. This is opposite to the batch processing or time-sharing models which allowed large expensive systems to be used by many people, usually at the same time, or large data processing systems which required a full-time staff to operate efficiently.

While early PCs owners usually had to write their own programs to do anything useful with the machines, today's users have access to a wide range of commercial and free software which is easily installed. The coming convergence of larger devices and the Personal Digital Assistants (PDAs), mobile phone and wearable computer markets which have similar functions, operating systems and even the same components, will decide if personal computer will refer to these devices.