A pen is a writing instrument which applies ink to a surface, usually paper. Pens range in colors, but are mainly found with black and blue ink. Pens may be categorized by the kind of tip on them. The main modern types are:
- ballpoint pens
- fountain pens
- rollerball pens
- marker pens
- Technical pens
- Space Pens
- Mechanical pens

Ballpoints, fountain pens and gel pens are sometimes erasable—their ink may be erased.
The ballpoint pen
There are two basic types of the ballpoint pen: disposable and refillable.
A power load that was very similar or the same as the ballpoint pen was developed by the Hungarian journalist Laszlo Biro. Biro developed a new tip consisting of a ball that was free to turn in a socket. The word used for ballpoint pens in Argentina is birome because Laszlo Biro lived there for many years; also, biro can be used to refer to a ballpoint pen in British English. It was originally invented for the British RAF, as problems occurred with fountain pens due to the low air pressure aboard planes in flight. He also made the pen shoot ink out when used incessantly. jason is cool