A chalkboard is a smooth, dark surface, usually mounted on a wall, that you can write on with chalk and then erase. For over a century, chalkboards were the main teaching tool in classrooms everywhere. Teachers would write lessons, math problems, and spelling words on the board while students copied them into their notebooks.

Chalkboards are typically dark green or black, made from slate or a painted surface that chalk shows up clearly against. The dusty white or colored chalk sticks leave marks that wipe away easily with an eraser (or even a damp cloth), letting teachers use the same board hundreds of times. Many older schools still have chalkboards, though they've been largely replaced by whiteboards and digital screens.

Some people prefer the term blackboard, which means the same thing. You might also hear someone say they're going to “write it on the board” when they mean the chalkboard. The gentle scratching sound of chalk on a chalkboard is familiar to millions of people who grew up before digital screens took over classrooms.