Question : routers

What is the difference between routers like Cisco routers and Cable/DSL routers?

Answer : routers

Well a Cisco router is a professional version of those mini ones.

The home Cable/DSL routers usually support a DHCP server (to give out IP's to the clients connected to them) and have very limited functionaliy (when compared to the cisco professional ones).  But 99.9% of what you would ever want to do can be done from one of those cable/DSL routers.  

People who have professional applications that require compliacted access lists (deny this IP, allow this certain IP only to access this port, etc, etc) use professional cisco routers that can handle all the extra functionaltiy and do it faster.

The cable/dsl ones allow you to usually forward a few ports(say 10) where a real router has unlmiited ability.

Cable/Dsl routers are degsigned for home situatuons so they provide IP's to a local network - a true router does not provide IP's it only directs/controls traffic on the internet.