Hey kiddo! Do you know what a spur is? It's a pointy thing that sticks out, like the spurs on a cowboy's boots. In architecture, a spur is a small, pointy projection that sticks out from the surface of a building, like a small triangle or a little tower.
Spurs can be decorative or functional. Sometimes, spurs are used to add extra support to a building's structure, like when a building has very tall walls that need extra reinforcement. Other times, spurs are just there to look pretty and add character to a building's design.
In some styles of architecture, like Gothic architecture, spurs are a really important part of the overall look of a building. Gothic buildings often have lots of spurs sticking out all over the place, like little spikes or towers.
So there you have it, kiddo! A spur in architecture is a pointy projection that can serve a functional or decorative purpose in a building's design.