What is the difference between an HDMI splitter and HDMI switch?

You use an HDMI splitter if, for example, you want to play games on your TV one time and on a large screen the other time. You don't have to change cables, this is done automatically.

You use an HDMI switch if you want to connect multiple devices to your TV with just 1 cable OR if your TV has fewer HDMI inputs than desired.

A matrix HDMI switch is an HDMI splitter and HDMI switch in one.

You use a matrix HDMI switch, for example, to play games on a large screen and play a movie on another screen at the same time. You don't have to change cables or reconnect equipment.