What is the definition of basic legal cover for car insurance?

Like if my car insurance company tells me that when driving other peoples cars, I have basic legal cover

Is this any different than third party cover? Like say I'm driving someone elses car how much am I covered

With my insurance it doesnt need to be an emergency for me to be covered driving someone elses car, just wondering how much I'm covered

Because I was told that that level of cover is less than third party cover

Thanks