OSPF in my own words

OSPF is a link state protocol, it does not exchange routes and metrics. The only thing that OSPF exchanges is the state of it's link and the cost associated with the link. As link state advertisement arrives from OSPF neighbors, the OSPF routers perform a series of computation on the LSA's and this gives the OSPF router a complete picture of the Network.

Shortest path first Algorithm(SPF). This is the series of computation performed by OSPF routers on received link state advertisement. Once the computation is complete, the result is what you see when you execute the command:
#Show ip ospf database

Before any LSA's adjencency is formed a neighbour relationship must be formed or must be discovered, LSA's are only sent if there is a change in the link status.