Connecting two or more personal computers using a standard hub or switch.

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The simplest kind of home network contains exactly two computers. You can use this kind of network to share files, a printer or another peripheral device, and even an Internet connection. To connect two computers for sharing these and other network resources, consider the options described below.

Connecting Two Computers Directly With Cable
The traditional method to network two computers involves making a dedicated link by plugging one cable into the two systems. Several alternatives exist for networking two computers in this manner:
· Ethernet crossover cable
· Null modem serial cable or parallel peripheral cable
· Special-purpose USB cables

Ethernet - Of the above choices, the Ethernet method is preferred as it supports a reliable, high-speed connection with minimal configuration required. Additionally, Ethernet technology offers the most general-purpose solution, allowing networks with more than two computers to be built fairly easily later. If one of your computers possesses an Ethernet adapter but the other has USB, an Ethernet crossover cable can still be used by first plugging a USB-to-Ethernet converter unit into the computer's USB port.

Serial and parallel - This type of cabling, called Direct Cable Connection (DCC) when using Microsoft Windows, offers lower performance but offers the same basic functionality as Ethernet cables. You may prefer this option if you have such cables readily available and network speed is not a concern. Serial and parallel cables are never used to network more than two computers.

USB - Ordinary USB cables must not be used to connect two computers directly to each other. Attempting to do so can electrically damage the computers! However, special USB cables designed for direct connection exist that can be used safely. You may prefer this option over others if your computers lack functional Ethernet network adapters.

To make dedicated connections with Ethernet, USB, serial or parallel cables requires
1. each computer have a functioning network interface with an external jack for the cable, and
2. the network settings on each computer appropriately configured
One phone line or power cord cannot be used to directly connect two computers to each other for networking.

Connecting Two Computers With Cable Through Central Infrastructure
Rather than cable two computers directly, the computers may instead be joined indirectly through a central network fixture. This method requires two network cables, one connecting each computer to the fixture. Several types of fixtures exist for home networking:
· Ethernet hubs, switches, and routers
· USB hubs
· Phoneline and powerline wall outlets

Implementing this method often entails additional up-front cost to purchase more cables and network infrastructure. However, it's a general-purpose solution accommodating any reasonable number of devices (e.g, ten or more). You will likely prefer this approach if you intend to expand your network in the future.

Most cabled networks utilize Ethernet technology. Alternatively, USB hubs can be employed, while powerline and phoneline home networks each offer their own unique form of central infrastructure. The traditional Ethernet solutions are generally very reliable and offer high performance.

Connecting Two Computers Wirelessly
In recent years, wireless solutions have enjoyed increasing popularity for home networking. As with cabled solutions, several different wireless technologies exist to support basic two computer networks:
· Wi-Fi
· Bluetooth
· infrared

Wi-Fi connections can reach a greater distance than the wireless alternatives listed above. Many newer computers, especially laptops, now contain built-in Wi-Fi capability, making it the preferred choice in most situations. Wi-Fi can be used either with or without a network fixture. With two computers, Wi-Fi networking minus a fixture (also called ad-hoc mode) is especially simple to set up.



References

www.computernetworking.about.com
www.networkingworld.net

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