In everyday life, entropy tells us how mixed-up things are! Much like how scrambled eggs can’t be “unscrambled.” In our case, physicists found that a black hole's entropy depends on its surface area. (event horizon).
If you were to find yourself in a black hole, time would be 'moving around you'. This is possible because inside the black hole, time acts differently than outside of it. We call this term ''time dilation.'' Black holes usually have enormous densities, as a study conducted in the early 2000s proved that in order to create a miniature black hole, you would need to squeeze something so large (presumably the size of manhattan) down to the size of a coin just to have a chance at creating one. With all that compactness going on, The physics we know start to fail at answering almost anything beyond this point.
In the 1970s, Stephen Hawking showed that black holes actually glow, slowly leaking heat in the form of radiation and, over a very prolongued period of time they can even evaporate completely. If information is truly lost, physics as we know it breaks down, hence the legendary quote ''matter cannot be created nor destroyed.'' But if it doesn't get destroyed then something must be preserving it. This process can also be refered to as ''hawking radiation''. As discussed, it is the instance where a black hole, converts its stored 'data' which is anything swallowed (e.g planets / stars) into other forms of matter such as radiation. This process however, take a very long time to manifest.
Scientists have theorised that black holes actually have an infinite mass. This can be very confusing, because if something has unlimited mass then why would its size not also be like that? In order to answer this, we need to look at something that's called the singularity.
Black holes are made up of 2 main sections. We actually discussed about the first one, the event horrizon, which acts as ''the point of no return.'' We call it that because of its immense gravitational field, which not even light can escape. The second, more inner section is the called the singularity which is made out of every piece of matter the black hole vacuumed throughout its life. It is theorised that because of the black hole's game breaking abilities, the singularity is actually the point of infinite density and zero size, meaning it has no volume and therefore is infinetly small.
Researchers see black holes as giant computers that store information in entangled 'quantum bits' with entropy tracking how that information is processed and eventually released. New work shows entropy can shift dynamically as black holes merge while modern theories such as string theory came up with a formula for entropy that is still in development as of today.