ballpoint pen

A ballpoint pen is a writing instrument that uses a small rotating ball (usually made of metal like tungsten carbide) at its tip to transfer ink onto paper. Inside the pen, viscous ink is stored in a reservoir. When you press the pen against paper, the ball rotates, picking up ink from the reservoir and depositing it smoothly onto the surface. This design prevents ink from spilling or drying out quickly, making ballpoint pens convenient, clean, and reliable for everyday writing. They are widely used due to their affordability, durability, and ease of use.