HDMI Splitter: It receives a signal from one device (e.g., a Nova/Cosmote box) and distributes it so that the same content is displayed simultaneously on two or more televisions.
HDMI Switch: It allows you to connect multiple devices (e.g. PS5, PC, TV box) to a single HDMI port on your TV and switch between them at the press of a button.
Splitter: General splitters that distribute a video or audio signal to more than one output.
Converter: Converters that change the type of signal, allowing you, for example, to connect an old device (Scart/RCA) to a new TV (HDMI).