Local Wireless Networks
Local Wireless Networks are often called different names WLAN, Wi-Fi, Hotspot, 802.11b/g/n, etc.
For the Home User a Local Wireless Network allows you to connect wirelessly (Usually via a Laptop) to your ADSL or Cable Internet Installation. This allows you to use the Internet around your Home within a Radius of approximately 50m.
This can also allow ANYBODY else to access your Internet Connection, and is why every Wireless Network should be secured with Wireless Encryption (Password).
Your Local Wireless Network radio signal can vary greatly in strength depending on what objects are in between your laptop and the Wireless Router Antenna, every wall or object will reduce the signal and brick or masonry will almost block the signal. Moving the Router so that there is a clear line of sight to the laptop, or less objects in the way, should fix this issue. Every location has its own issues, and must be resolved on a Case by Case basis. Repeater Stations can also be installed to extend the Signal Range or get around obstacles.
The Wireless Signal can also be subject to interference from other radio waves and suffer dropouts; this can be easily rectified by changing the Channel.