Cross Cable and Straight Cable - Network

Straight Cable

1 - Connect a computer to a switch/hub's normal port. 
2 - Connect a computer to a cable/DSL modem's LAN port.
3 - Connect a router's WAN port to a cable/DSL modem's LAN port. 
4 - Connect a router's LAN port to a switch/hub's uplink port. (normally used for expanding network).
5 - Connect 2 switches/hubs with one of the switch/hub using an uplink port and the other one using normal port.

Crossover Cable  

1 - Connect 2 computers directly.

2 - Connect a router's LAN port to a switch/hub's normal port. (normally used for expanding network)
3 - Connect 2 switches/hubs by using normal port in both switches/hubs.