There are three classes of routing protocols: link state, distance vector and advance distance vector (or hybrid). Hybrid means that a protocol has certain characteristics of both distance vector and link state protocols.
Distance vector protocols hides the network topology. The router is only aware of its connected neighbors. The examples are RIP and EIGRP. Classic distance vector protocols such as RIP re-send routes periodically to confirm that they are still valid. EIGRP is a hybrid or advance distance vector.
Link state protocols such as OSPF have complete topology visibility. Instead of re-sending the routes, they exchange Hello packets to the same effect - confirm that all previously sent routes are still good. They only update the routes when something is changed; for example, a link goes down.