A Satellite tournament is a tournament where you can entry into another poker tournament, typically, a larger tournament with a higher buy-in.

Satellite tournaments allow you to enter major tournaments without having to pay the entry fee or buy-in.

Online satellite poker tournaments are variations of a Multi Table Tournaments which rewards players to succeed without busting.

Buy-ins for online poker satellite tournaments are typically smaller than buy-ins for the main tournament.

Satellite tournaments can run mini-satellites which are tournaments to qualify for satelllite tournaments. Ofen you see mini-satellites allow players to use their FPPs or Frequent Player Points to enter these mini-satellites.

Here's an example:

Say you want to play in the WSOPE. Betfairpoker are running regular tournaments where the buy-in is $525. At these tournaments Betfair will give away WSOPE Seats.  Betfair recognise that not all players can or want to pay $525 to enter these regular tournaments so runs online satellites and freerolls to the satellites to encourage more people to try and compete for seats at the WSOPE tournament.  Currently there are several levels of satellites which allow you to compete for your place in their WSOPE Seat Tournaments from $7.