When your exam period approaches, do you do homework or study in a cafe as well as in the library? The same goes for Koreans.
Korean cafes are actually crowded with people who study. We call them the 'Ka-gong-jog', which mean is a bunch who study at a cafe.
What is different from foreign countries is that Koreans are free from their bag or stuff.
Yes, you can throw your bags away to get a good seat and go order or even leave the cafe altogether!
When you return to your seat, your luggage will remain in your place, as always, to prevent others from sitting down.

The other thing that's unique is that the information about Wi-Fi is written on the receipt.
You don't have to walk around the hall or ask the staff a Wi-Fi. It's convenient, isn't it?