Yeah seems pretty stupid to me. The best use would be to store hashes that convert to anything. A hash can convert into an entire book for example, and you can store the hash string for peanuts.
Pretty stupid is that you don't understand hashes. A hash - doesn't 'convert into an entire book' - or anything.
How did the community get so many dumbasses?
It should be noted - Sha256 does not encrypt the data/content of your string, it instead generates a fixed size hash, using your input string as a seed.
This being the case - He got the idea wrong but he is right in the sense that I could feed in the content of an encyclopedia, which would be easily 100 mb in size of text, but the resulting string would still be 256 bits in size, but its impossible for you to reverse the hash, to get that 100mb of data back out of the fixed size hash, the best you can do, is try to guess / compute the seed data, hash, and then see if the hash matches the hash your trying to break.
If you could reverse the hash, you would have the greatest form of compression to date.
In any case, no need to be rude for no reason, we are here to learn, probably not even a native speaker. Now get your frustrated ugly bald head out of this forum and go back to being wrong on Youtube.