On the left hand side are devices that use straight-through cable and on the right hand side are devices that use crossover cables.
These are the devices that use a straight-through cable:

• Switch – Router
• Switch – PC
• Switch – Server
• Hub – PC
• Hub – Server

These are the devices that use a crossover cable:

• Switch – Switch
• Switch – Hub
• Hub – Hub
• Router – Router
• Router – PC
• Router – Server
• PC – PC

But nowadays the standard is becoming obsolete due to the fact that Auto-MDIX (automatic medium dependent interface crossover) technology on devices grows with each device that supports it. This means that ports do not need to know what type of cable is used when you connect two devices.