What actually is a car platform, anyway?

Volkswagen's MQB is among the most prominent platforms, spawning a variety of models
The word is commonly used in automotive circles, yet its meaning isn't widely understood – and is highly variableOne thing the car industry is renowned for is jargon – and the problem with jargon is that terms can be interpreted differently depending on who's using them.
Electric vehicles' traction motors are an example. Are those that avoid the use of permanent magnets separately excited synchronous