Byzantine architecture is like building blocks that ancient people used to create big buildings that looked very fancy and impressive.
These buildings had big, strong walls made of stone that looked very tough and could withstand attacks from enemies. The buildings were also really tall and had big, round domes on top that were made of bricks and supported by many pillars.
Inside the buildings, people would see colorful, detailed artwork covering the walls and ceilings. The decorations were usually pictures of holy people and important events, like when Jesus was born or when he died.
One cool thing about Byzantine architecture is that it blended lots of different styles from different places. For example, some of the buildings had Roman and Greek influences, while others were inspired by eastern cultures like Persia and Syria.
Overall, Byzantine architecture was a really fancy and impressive way of building that ancient people used to make beautiful and strong buildings that are still loved and admired today.