What exactly is Line Training?

[Callsign Kilo]

Hey guys

Sorry if I am asking something that has been asked before, however I am keen to know what line training on type involves?

I know it follows a type rating, however is it company specific? For example does the 100 hrs line training that Bond Aviation offer on their 737's exempt you from the cost of further line training if you were to get a job with the likes of Ryanair after your training??

Thanks in advance