What is a wireless access point?
A wireless access point is a device that communicates with a computer's and devices via radio waves to provide network connectivity.
What is an SSID?
An SSID is the name of a wireless radio signal (e.g. HWS-Private). It identifies a particular set of network services offered from the access point.
What is "roaming"?
A wireless computer can "roam" from one access point to another, depending on the strength of the signal coming from the access point. Your wireless network card will negotiate the best connection, and move from one access point to another transparently.