A ballpoint pen is a pen that takes out the writing medium by rolling a ball at the front end of a pen or refill. Ballpoint pen is a kind of pen that uses tiny rotating balls, which are made of brass, steel or tungsten carbide, and can release ink to paper when writing.
Pen is a writing tool with metal as the main body. It contains ink (mostly black or blue) through a hollow pen tube, and then writes through a duckbill pen through gravity and capillary action. It can be said that it is a writing tool of western calligraphy.