What switching methods are there?

A coin-operated timer can switch (make a connection) in several ways; the most common method is directly switching the power supply (230 volts) as soon as a coin is inserted and the timer starts.
If, for example, a lamp is connected to the coin-operated timer, that lamp will stay on for the set time.

The direct switching of the power supply from the coin-operated timer can be 24 volts or 230 volts. 

With direct switching, the power capacity you need to switch is also important. 
1000 watts is standard, which means the device being switched must not exceed 1000 watts. The power rating is usually indicated on the device itself.
7000 watts is possible as an option; this will always be sufficient for a device because it is more than can be connected to a normal power outlet (the max is 3500 watts on a 16A fuse).

Another possibility is a so-called potential-free contact, where the coin-operated timer only creates a connection between two terminals. This is used, for example, when switching a device that already has a dedicated connection for a coin-operated timer.