How to choose a button for your equipment
Buttons, toggle switches, switches, circuit breakers, triggers, all types of switching, differ primarily in design (overall dimensions, key size) and functionality (lock, pressure safety device, reverse or speed control, additional soft start circuit, switching modes, etc.)
Here are some international standards:

SPDT - Single Pole, Double Throw. One pole, two directions. There is one common contact (pole), which can be connected to one of the other two contacts. In Russian circuitry, this is called one contact group.
DPDT - Double Pole, Double Throw. Two poles, two directions. Two contacts (poles), each of which can be connected to one contact or the other. In Russian, these are called two groups of contacts. Each group is not electrically connected to each other. Each of them can switch completely different circuits. They have only one thing in common: they operate simultaneously.
There are switches that have many more sets of contacts than just two. For example, relays, which are themselves electrical switches, with four sets of contacts are quite common.
SPST - Single Pole, Single Throw. One pole, one direction. One contact can be connected to one other contact or disconnected from one other contact. This is also one group of contacts, but not complete.