Do you mean, if somebody calls somebody an "associate" rather than a friend? (Or is this something else?) If so, an associate is somebody you know, maybe talk to a lot, but wouldn't consider close enough to be a friend. They could be co-workers (so people you'd speak to every day at work, but wouldn't tell your secrets to or spend time with outside of work) or just friends of friends, etc.
Somebody might say, "hey you're friends with Jane aren't you?" and you might say "not really, she's more of an associate" to explain that you know who she is and have spoke to her, but you're not close. Some people have higher standards to what constitutes as a "friend" than others, so it's an individual thing. Personally, unless I meet up with them in my free time, specifically with them (i.e. not as a group thing) I probably wouldn't call them a friend - with perhaps one exception.