Like lines and curves, texture is yet another strong element of detail that needs to be communicated in a good photograph. It is about as how you feel about anything. It is about the feel of touch and the reaction. In photography, it could be known as the visual understanding of your physical touch without really touching.
Almost everything has some texture: rough or smooth, patterned or irregular, dramatic or subtle. It could be understood as the surface details that exist physically.
For me textures are about our feelings about the finish of any subject. It is more emotional than physical. It affects our comfort level of being with it. Imagine holding a dragon reptile in your hand and a silky feathered dove on the other hand. How do you feel looking at a rocky mountain and the fine sands of a silent beach?
Everything that exists on earth has a texture that emotionally disturbs you knowingly or unknowingly. They may be either man made or natural. As a photographer, could you really bring in the feel of these emotional disturbances of through the visual impact of different textures? In a sense, texture enables the eyes to touch the subject.
Look at the world around to understand as how the visual feel about the textures are changing when the quality of the light changes, during the different time of the day. The feel of texture also changes when the angle from which you see it changes.
It’s all the variations in the shadows and high lights that make the texture look different even if it feels the same.