* Notebook paper: Commonly lined or gridded paper found in notebooks and pads.
* Letter paper: Usually unlined, and often comes in various sizes and weights, often used for correspondence.
* Card stock: A thicker, sturdier paper, sometimes used for formal invitations or announcements.
* Specialty papers: Papers with textured surfaces, different colors, or other unique characteristics.
Essentially, writing paper is any paper intended primarily for the purpose of handwriting or drawing.