A bollard is a short, sturdy post designed to protect buildings, sidewalks, and people from being hit by vehicles. You've probably seen bollards many times without knowing their name: those thick posts outside grocery stores, along bike paths, or in front of important buildings. They look simple, but they're incredibly strong, often made of steel or concrete with reinforcement.

Bollards work by creating a physical barrier that cars and trucks can't easily push past. Near a busy shopping area, bollards might line the sidewalk to keep pedestrians safe from cars that accidentally jump the curb. Around government buildings or airports, heavier bollards provide extra protection. Some bollards can even retract into the ground when authorized vehicles need to pass through.

Maritime bollards need to withstand enormous pulling forces from huge ships, so they've always been built incredibly tough. The protective posts on streets borrowed both the name and the principle: a simple, strong post anchored deep in the ground.

You might also see decorative bollards that serve the same protective purpose but look nicer, perhaps shaped like traditional lampposts or painted to match a neighborhood's style.