Just Synapses

You can ship characters for happily ever afters, sure, you can ship them for tragically-then-happily, you can ship two or three or four or more, you can ship endless combinations of personality types and relationship dynamics

but you can also ship characters under very specific circumstances, or for a certain period of their life but not for all of it, or only in a certain universe. You might say “I ship these characters” and what you mean is you think they are fascinating together and could have a story together. That story could be any kind of story. 

Sometimes it means you want them together for the rest of their lives. Sometimes it means something different than that.