Final answer:
The two categories of surface texture are rough and smooth. Texture can be added to artworks to create visual effects or mimic the feel of different materials. Artists achieve texture through various techniques such as brushwork, layering, or choice of materials.
Step-by-step explanation:
The two categories of surface texture are known as rough and smooth. Texture refers to how a surface feels or looks in terms of roughness or smoothness. In art, texture can be added to a two-dimensional or three-dimensional piece to create a certain visual effect or mimic the feel of different materials, such as rock, wood, or fabric. Artists achieve texture through brushwork, layers of paint, or the choice of materials.