Difference between Firewall and Router

Question

I can do VPN remote access configuration by using cisco firewall also I can do it using the cisco router by using the SDM program so what is the benefits from using the firewall or all of them are the same?
I mean it's recommended to use the firewill? if yes, why ?

Answer 1

Answer-
1) WE can make Security-Level on Firewall,but router can't
2) We can make firewall in multiple context(Virtual Firewall) but router can't
3) We can create SSL VPN on Firewall,but router can't
4) Whenever a packet inspected by Firewall and another packet comes with same contents then firewall didn't check that packet,
  but router checks all packets.(show connections)
5) Firewall works as L2 and L3 both, but router only on L3.
6) Firewall inspects packets on L3 to L7 but router works on L3.
7) Firewall have Failover,router can't
8) Whenever we take trace,then firewall cannot comes on picture,but router always shows as a Hop Count.