Universal Serial Bus(USB)

Stands for "Universal Serial Bus." USB is the most common type of computer port used in today's computers. It can be used to connect keyboards, mice, game controllers, printers, scanners, digital cameras, and removable media drives, just to name a few. With the help of a few USB hubs, you can connect up to 127 peripherals to a single USB port and use them all at once (though that would require quite a bit of dexterity). USB is also faster than older ports, such as serial and parallel ports. The USB specification supports data transfer rates of up to 12Mb/sec and USB has a maximum transfer rate of 480 Mbps. Though USB was introduced in 1997, the technology didn't really take off until the introduction of the Apple iMac (in late 1998) which used USB ports exclusively. It is somewhat ironic, considering USB was created and designed by Intel, Compaq, Digital, and IBM. Over the past few years, USB has become a widely-used cross-platform interface for both Macs and PCs.

Central Processing Unit(CPU)

A CPU (Central Processing Unit) is an important part of every computer. The CPU is like the brain; its job is to carry out instructions and calculations.
The CPU is an electronic machine that works on a list of things to do. It reads the list, one item at a time, doing each instruction in order. A list of instructions that a CPU can read is a computer program. A machine that can perform the job of a CPU is often called a Turing machine by mathematicians.
Here are some of the basic things a CPU can do:
Add two numbers together
Test to see if one number is larger than another
Move a number from one place to another
Get a number from memory
Jump to another place in the instruction list
Even very complicated programs can be made by combining many simple instructions like these. This is possible because each instruction takes a very small time to happen. Many CPUs today can do more than 1 billion instructions in a single second. In general, the more a CPU can do in a given time, the faster it is. One way to measure a processor's speed is MIPS. Flops and CPU clock speed (usually measured in gigahertz) are also ways to measure how much work a processor can do in a certain time.
A CPU is built out of logic gates; it has no moving parts. The CPU of a computer is connected electronically to other parts of the computer, like the video card, or the BIOS. A computer program can control these peripherals by reading or writing numbers to special places in the computer's memory.

Monitor

A monitor or display (sometimes called a visual display unit) is a piece of electrical equipment which displays images generated by devices such as computers, without producing a permanent record. The monitor comprises the display device, circuitry, and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), while older monitors use a cathode ray tube (CRT).

modem

modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.
Fortunately, there is one standard interface for connecting external modems to computers called RS-232. Consequently, any external modem can be attached to any computer that has an RS-232 port, which almost all personal computers have. There are also modems that come as an expansion board that you can insert into a vacant expansion slot. These are sometimes called onboard or internal modems.

Hardware

A personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator's desired functions.
TypTypical PC hardware
2 Motherboard
2.1 Power supply
2.2 Video display controller
2.3 Removable media devices
2.4 Internal storage
2.5 Sound card
2.6 Other peripherals
2.6.1 Input ical PC hardware

Software

Computer software is often regarded as anything but hardware, meaning that the "hard" are the parts that are tangible while the "soft" part is the intangible objects inside the computer. Software encompasses an extremely wide array of products and technologies developed using different techniques like programming languages, scripting languages, microcode, or an FPGA configuration. The types of software include web pages developed by technologies like HTML, PHP, Perl, JSP, ASP.NET, XML, and desktop applications like OpenOffice, Microsoft Word developed by technologies like C, C++, Java, C#, or Smalltalk. Software usually runs on an underlying software operating systems such as the Linux or Microsoft Windows. Software also includes video games and the logic systems of modern consumer devices such as automobiles, televisions, and toasters.
Computer software is so called to distinguish it from computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. At the lowest level, software consists of a machine language specific to an individual processor. A machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. High-level languages are compiled or interpreted into machine language object code. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler.
The term "software" was first used in this sense by John W. Tukey in 1958. In computer science and software engineering, computer software is all computer programs. The theory that is the basis for most modern software was first proposed by Alan Turing in his 1935 essay Computable numbers with an application to the Entscheidungsproblem.

Computer

Computer is the latest device of the world.The computer is very much useful for this modernisation world.It has given a lot of benefits for the humankind.Its uses is whole over the world so that we caln talk and even see what is happening in every corner of the world through network connection.also we can chat and visit sites from one corner to other corner of the world through its connection.