What is a transit center?

If you're travelling anywhere on public transport and you see on a map that there is a "transit center", what does it mean?

This may seem like a simple and uninteresting question (simple to most, yes; uninteresting to all but transit geeks, probably). While no particular definition exists, I could easily make some assumptions if you were to state you were at one. First, I'd immediately assume you were in the US or Canada. This is because I have never heard of a transit center anywhere outside of North America outside from a different name for "central station" here or there. And just exactly how would you describe a transit center to someone else?

Is it a point where one line meets another? Two? Where's the line to draw between a simple transfer point and this mythical place called a "transit center"?

Tokyo would have more transit centers than anyone else. Image source: Tokyo Metro

Perhaps it comes down to amenities: toilets, shops, shelter, etc. Maybe it comes down to frequency: at any point, you're going to see a transit vehicle (or two, three, or ten). One thing that all transit systems seem to have in common who use this terminology is that they all seem to be low-frequency, slow, and inconvenient systems. In other words, they're in places with poor transit. They're used to make a system sound more friendly and important than it really is.

This is a "transit center" in Portland, Oregon. More info here.

What is a transit center? Whatever you want it to be.