Motherboard ports are the inputs or connection points where components are connected, including the ports on the back of a computer.
Motherboards explained
If you are replacing an internal hardware component or performing an upgrade for better performance, you must remove the existing equipment from the designated motherboard port. To install new components, do the opposite and connect the new component(s) to a designated port.
There are also external ports on the back of the motherboard, for connecting and disconnecting peripherals. Without opening the case, you can connect a mouse, keyboard or external hard drive to the USB ports on the top or back.
There are different types of internal ports, including PCI-e, SATA, CPU, and so on. There are also external ports such as USB, PS/2, RJ-45, and so on. Both are referred to as ports.