that is not a fork. what you say is a bunch of terminology regarding new blocks and what happens to them in different cases like when the block has not parent. read it here: https://bitcoin.stackexchange.com/questions/5859/what-are-orphaned-and-stale-blocks

a fork in programming is when you "copy the original code" for yourself to change it.
but a fork in bitcoin is when you change the "rules" of bitcoin. for example changing consensus rules about block size. some refer to it as "making something that was invalid before, valid. or making something that was valid before, invalid"
in case of the list i mentioned here, these people are changing something about bitcoin. some increase the block size some change the algorithm, change the supply,... this change results in a new chain and a new coin which we call an "altcoin".