Ethernet: Straight-through VS Crossover Cable
From Lucca's Wiki
Straight-Though
PC <=> Switch Router <=> Switch
Crossover
PC <=> Router Router <=> Router Switch <=> Switch
Exceptions and notes:
Consumer routers generally have one router port labeled [INTERNET] and four switch ports. If you want to connect a PC to any of the ports NOT labeled [INTERNET], you'd use a straight-through cable in that case since they're technically switch ports.