A stop is double the amount of light. Useful for equivalence across different ways of changing exposure. So I halve my shutter speed I’ve lost a stop. But I increase my aperture from 4 to 2.8 I’ve gained that stop back. Or I double the sensitivity of my film or sensor (eg. iso 400 to 800).
So yes, in terms of data if using linear gamma exactly equivalent to bits. This is why log gamma curves are used to store for eg 16 stops of light info in 12 bit format
Imagine light represented as a floating point number of the type a * 2 ^ b
Stops describes the range of the exponent b.
With a typical cinema camera, max_b > min_b + 14
You can use tricks like gradient ND filters to increase the perceived range within of a frame or variable NDs to slowly adjust over time (like our eyes do)
