Reed pens are the oldest known type of pen. They were made from reeds growing in the delta of the Nile. The ancient Egyptians invented them, and also invented black ink, using soot and gum arabic. Their pens had split nibs to regulated the flow of ink to the writing tip. This simple design is still used in calligraphy today.
Quill pens are one of the oldest type of pens. A quill pen is the feather of a bird, usually a goose. The end of the feather (the quill) was kept very sharp and had to be dipped into ink after every few words.
A stylus is a pen that cannot write on paper, but can write on clay or wax. Styli of wood or metal have been used for thousands of years, for example in cuneiform writing. A modern computer stylus is usually made of plastic and may have electronics inside. It is used with a touchscreen.