What are channels?

After having many problems with my wireless connection I decided to
experiment with the channel the router was set to. The channel was origanally
6 but i was constantly being disconnected from the connection. I then changed
the channel to 1 and my computer could find no network available however all
other computers on the network were still fine. I then changed the channel to
13 and my computer found the network connection ammediately nd has remained
connected for lnger than usual however I have not tested yet to see how long
(so far so good). Why has this happend with the channels is there a reason
for one channel working much better or is it just shear coincidence?

Cheers Screamer