External devices connect to the computer on the back. The diagram on the left shows the most common connections. The arrangement of these is quite varied from machine to machine. The name-brand computers often have unique designs with special connectors for the peripherals that are sold with the computer. There is a standard color scheme for ports and connectors, but not all manufacturers used it.

Connectors come in two types: male and female. The male has pins while the female has holes.