Explanation:
Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco proprietary routing protocol, so it is vendor-specific. By default, EIGRP internal routes have an administrative distance value of 90. OSPF uses cost as its metric. By default, the cost of an interface is calculated based on bandwidth with the formula cost= 10000 0000/bandwidth (in bps). OSPF elects a DR on each broadcast and nonbroadcast multiaccess networks (like Ethernet and Frame Relay environments, respectively). It doesn't elect a DR on point-to-point link (like a serial WAN).
Topic 3, IP Services

Link State Routing Protocols
http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=4
Link state protocols, sometimes called shortest path first or distributed database protocols, are
built around a well-known algorithm from graph theory, E. W. Dijkstra'a shortest path algorithm.
Examples of link state routing protocols are:
Open Shortest Path First (OSPF) for IP
The ISO's Intermediate System to Intermediate System (IS-IS) for CLNS and IP
DEC's DNA Phase V
Novell's NetWare Link Services Protocol (NLSP)
Although link state protocols are rightly considered more complex than distance vector protocols,
the basic functionality is not complex at all:
1.Each router establishes a relationship-an adjacency-with each of its neighbors.
2.Each router sends link state advertisements (LSAs), some
3.Each router stores a copy of all the LSAs it has seen in a database. If all works well, the databases in all routers should be identical.
4.The completed topological database, also called the link state database, describes a graph of the internetwork. Using the Dijkstra algorithm, each router calculates the shortest path to each network and enters this information into the route table. OSPF Tutorial http://www.9tut.com/ospf-routing-protocol-tutorial