Care

1. A sarcastic way of saying "I don't care."

2. An ironic form of saying "I don't care."

The differences are how they are conveyed in a particular situation, or who it is conveyed to.

Sarcasm : Person 1. "I can deadlift 430lbs" Person 2. "Care"

Irony/Sarcasm : Friend 1. "Guys, i just looked, and im down 75lbs now!" Friend 2. "Care" *all friends laugh*

Irony : Friend 1. "Yeah bro, i dropped 32 kills in warzone yest-" Person 1. "Warzone?! I love that game, i win every single game i play." Friend 2. "Care" *Friends laugh* Person 1. *confused* "Thanks, we should play some time!"