What is the name of the format mask "225.255.255.0" and "/24"? And how to translate "225.255.255.0" to "/24"?

Question

Computer networks

And then I wanted to write in Google about how to convert "/24" to "225.255.255.0" and realized that I don't know how these forms of writing masks are called

Answer 1

225.255.255.0 - convert to binary SS -> 11111111.11111111.11111111.00000000 - 24 ones, so /24 in short notation, since the mask always looks like first one in a row, at the end - zeros in a row

Answer 2

https://habrahabr.ru/post/314484/

Answer 3

I recently encountered a similar one: I just wrote "network mask online" - I always forget how to distribute units by octets there)