Hello, does anyone know what each relay in the engine/central/rear compartments do ?

After 1 hour looking on itopix couldnt find an answer. I can find easily what fuses mean, but what do relays do i couldnt find. Thanks.

Have a look here https://www.jaguarforums.com/forum/x...11-xjl-186137/ and look in the BATTERY, MOUNTING AND CABLES section