How Horsepower Works

The word "horsepower" is constantly mentioned regarding car and industrial engines. This edition of How Stuff Works defines the term, and explains how to measure it.DefinitionThe term horsepower was coined by engineer James Watt, who is most famous for his work on improving the performance of steam engines.

How Computer Memory Works

Although memory is technically any form of electronic storage, it is used most often to identify fast, temporary forms of storage. If a computer's CPU had to constantly access the hard drive to retrieve every piece of data it needs, it would operate very slowly. When the information is kept in memory, the CPU can access it much more quickly.

How Email Works

An e-mail message is a simple piece of text sent to a recipient. E-mail messages tend to be text, although the ability to add attachments has become increasingly important. To look at e-mail messages, you use an e-mail client. Many people use well-known, stand-alone clients, such as Microsoft Outlook, Outlook Express, Eudora, or Pegasus.

How Ethernet Works

Ethernet is a local area network (LAN) technology with networks traditionally operating within a single building, connecting devices in close proximity. At most, Ethernet devices should have only a few hundred yards of cable between them. For two devices on a network to successfully communicate, they must both understand the same protocol.

How Encryption Works

Encryption is the process of encoding information in such a way that only the computer with the key can decode it. Most computer encryption systems are either symmetric-key encryption or public-key encryption Symmetric-key encryption is a secret code that each of the two computers must know in order to decode the information.

How Computer Viruses Work

Computer viruses are called viruses because they share some of the traits of biological viruses. A computer virus passes from computer to computer like a biological virus passes from person to person.A biological virus is a fragment of DNA inside a protective jacket. Unlike a cell, a virus has no way to do anything or to reproduce by itself.

How Serial Ports Work

The serial port has been an integral part of most computers for more than 20 years. Serial ports provide a standard connector and protocol to let you attach devices, such as modems, to your computer.All computer operating systems in use today support serial ports. Parallel ports are a more recent invention and are much faster than serial ports.

How Parallel Ports Work

The parallel port is the interface most used for printers. They are also used to connect a PC to scanners, CD-writers, external hard drives, Zip removable drives, network adapters, and tape backup drives.Parallel port basicsIBM originally developed parallel ports to connect PCs to Centronics printers.

How Bearings Work

The bearing makes many of the machines we use every day possible. Without bearings we would constantly be replacing parts that wear out from friction.Objects roll more easily than they slide. The wheels on your car are like big bearings. If you had something like skis instead of wheels, your car would be much more difficult to push down the road.

How Bluetooth Short-range Radio Systems Work

Bluetooth is a new standard developed by a group of electronics manufacturers that will allow certain electronic equipment to make its own connections, without wires, cables, or any direct action from a user. Bluetooth is intended to be a standard that works at two levels:Bluetooth is intended to get around the problems that come with both infrared and cable synchronizing systems.