Unless it's someone I have frequent contact with, (or, sometimes, semi-frequent or less if they did something more memorable), then when I see them I'll recognize them as familiar, I'll know that I know them, but not be able to connect their name to them. Normally, I associate who someone is and what I've done with them/how I know them with their name, so when they remind me of their name I then remember who they are completely. Sometimes, however, especially if it's been an extremely long time or I've met them perhaps fewer than three times and not recently, while their face may look familiar, their name won't ring a bell (unless it's online where I can't see their face, in which case the name may sound familiar but not be able to connect them to the person), and I won't remember who they are until I'm reminded of something they've done/how I met them/etcetera. I don't even always remember all of the things together, infrequently I'll have several different mental "persons" based off the splitting of interactions with what turns out to be one person. In line with that, sometimes when I find out something they've done, that'll be the only thing that I'll remember, until something sparks another memory with them.