How does wireless internet work?

A signal is sent wirelessly by high frequency radio waves to repeater stations, or wireless towers, at very low power (100mW or less).  From here, the internet signal is sent directly to the customer's antenna, which feeds his own radio receiver/transmitter, called a bridge.  The bridge converts the signal to a format which is understood by the computer's network system, and is connected to the computer network system either wirelessly (via an additional wireless router), or directly by cable.

The customer's antenna must have line of sight to the wireless tower (repeater), and will not work if there are any obstructions, eg trees, unless he is very close to the tower. 

As can be seen, only a short cable is used between the antenna and the bridge.  Therefore, the risk of lightening damage is much less than with dial up connections, where the telephone line is exposed for kilometers to the elements.