For your laptop to connect to your Wireless Network it must have a wireless adapter or wireless NIC. Such adapters are small radio transmitter / receivers which allow your Laptop to send and receive radio signals.
Three main types of Wi-Fi adapters are available: Wireless Nics, PCMCIA cards and USB Wireless Adapters. Some newer laptops and computers come with integrated wireless adapter chips.
All common adapters support either Ethernet (wired) or Wi-Fi (wireless) standards. USB Wireless Adapters are usually small and connect to your laptop through a USB port. An advantage to a USB type Adapter is that it can be swapped between laptops or desks easily.
Two kinds of wireless USB adapters are marketed by some manufactures; A "compact" model for travelers and a "basic" model for office or home use.
These adapters draw their power from the host laptop or computer and therefore do not require a separate power cord. The adapter's wireless antenna is always external to the computer and on some units the antenna can be adjusted manually to improve the Wi-Fi reception.
Because of the small size of these adapters and the fact that they are easy to setup they are a very attractive choice for those who want a network setup that is simple.
Some wireless network users prefer to buy a brand of adapter that matches the router that they have or are purchasing. Some manufactures even sell the router and adapters as a bundle referred to as a home network kit.
For security reasons it is best to disable wireless network adapters when not in use. This capability is typically provided by the adapter's software.