Celosia is an outdoor summer annual, but lately flower shops have been selling dwarf ones as "living bouquets", normally intended to be enjoyed for a few weeks and discarded. You can keep them indoors in a sunny window if you want to, but they will essentially die of old age after a couple of months.

I have given up on celosia, they are a waste of money in my opinion. Shame, because they look really nice. Before I knew they only lasted a few months, I thought I was doing something wrong, and kept buying them and trying to get them to survive.