Okay kiddo, you know how buildings can look very different depending on where they are and what time period they were built in? In medieval Serbia, which was a really long time ago, the buildings looked a certain way that we call "medieval Serbian architecture".
One thing that was important in this style of architecture was little details carved into the stone or wood, like flowers or animals or people. These buildings also had lots of arches and domes, which are like big curvy shapes on top of the building.
Another thing you might notice is that these buildings often had big walls all around them, like a fortress or castle. That's because back then, Serbia was sometimes at war with other countries, and those walls helped protect the people inside.
One famous example of this type of architecture is the Studenica Monastery, which is a big church with a bunch of smaller buildings around it. It was built over 800 years ago, and people still go there to visit today.
So that's a basic explanation of how buildings in medieval Serbia looked. They had lots of little details, arches and domes, and walls around them to keep people safe. Cool, huh?