An eraser is a small tool made of rubber or similar material that removes pencil marks from paper. When you make a mistake while writing or drawing, you rub the eraser over the marks and they disappear, leaving the paper clean so you can try again.

The most common type is the pink or white rectangular eraser that sits on the end of many pencils or comes as a separate block. Art erasers come in different types: kneaded erasers are soft and moldable, perfect for lightening drawings without damaging the paper, while gum erasers crumble as they work, lifting graphite cleanly away.

Erasers work through friction. The rubber material is slightly sticky, so when you rub it across pencil marks, it picks up the graphite particles and rolls them away into those little rubbery crumbs you have to brush off afterward.

The ability to erase changed how people learned and created. Before erasers became common in the 1770s, mistakes meant starting over or living with crossed-out words. Now you can experiment freely, knowing that wrong answers or wobbly lines aren't permanent. That freedom to make mistakes and fix them is what helps you learn: you can sketch different ideas, work through math problems, and refine your work until it's right.