Texture (Tactile Texture)
A surface's tangible structure, perceived visually or by touch, distinguished from Pattern by describing surface quality rather than a repeating motif.
In practice
Texture is the surface quality of a material: how rough, smooth, soft, grainy or glossy it is, felt by touch or inferred by sight. Designers choose it deliberately, such as uncoated paper for a warm, handmade-feeling book, a soft-touch coating on a premium box, or a fine grain on a phone case to hide fingerprints. On screen, texture can only be suggested visually, through photography or noise.
Often confused with Pattern
Texture is the quality of a surface; a pattern is a repeating motif laid onto a surface, which may or may not be tactile.
Try this
Collect five paper samples, close your eyes, and rank them by texture from smoothest to roughest.