There are so many cars in Korea. They have to park somewhere. They end up parking almost everywhere and anywhere.
For those living in the big apartment complexes, there are big parking lots. But, if you don't live there, you can't park there without special permission. They have parking attendants that keep a close watch on who is parking there. If there is a car that is not on their list, they stick a big yellow warning sticker on the window. The stickers are NOT easy to get off and require some chemicals and scraping.
Most of the main roads have no parking signs.
There are no no-parking signs in a lot of the residential areas. It is mostly 2 way streets, but there is barely enough room for one car to go through because in most cases, cars are parked on one or both sides. For the most part, I think those that live here have first dibs on the spots in front of their homes. If they are not there, you can park there. If they return and want you to move, they will phone you.
In Korea, everyone leaves their contact number (cell phone number) in the window. That way, if you are parked in someone's spot, or in someone's way, they can phone you. Some parking spots in the little villa homes around here, are set up so that one car parks behind another. If the inside car wants to get out, they have to phone the owner of the outside car to have them move it. I guess it would be a big problem if they were not around to move it.
In some of the big store parking lots, once they start getting full, the cars are parked behind and perpendicular to the other parked cars and set in neutral. When the other cars need to get out, that car is just pushed forwards or backwards out of the way.
You have to be very good at parallel parking in Korea, as they park almost bumper to bumper. In some cases, you have to phone to have cars moved, if they have parked too closely.