How do wireless routers work?

[Eric]

ok you are going to have to bare with me on this because i dont know anything about wireless routers.Ok i live in a Rural Area and can only get Dial-up and Sattelite (as far as i have checked) and i want to know if u go and buy a wireless router when u install it will u automatically get fast internet or do you have to get internet from an ISP and set it up with the router because a neighbor like 1/4 of a mile up the street has a wireless router and i need to know how this works so i can be sure i will be able to use it before i buy it