There are 3 main types of immobilisers to consider...
This type of immobiliser works by an electronic coded key that has to be inserted into the dashboard before you start the engine.
This type of immobiliser works by wireless signal from a keyfob so when you enter the vehicle you can start up the engine without having to insert a touchkey.
This type of immobiliser also works by wireless signal from a keyfob but you need to press a botton on the keyfob to mobilise the engine.