Q. I heard an animator talk about texture in drawing. Could you explain what he’s talking about? I haven’t a clue.

A. I’ll bet I could tell you the name of that animator.  I’ve heard his speech on texture many times, and he is justified in talking about it.  It’s an extremely important principle; let’s see if I explain it? 
What if all forms of music were played at the same tempo, and by the same instruments?  Boring, right?  What if all food tasted the same, or all your clothes felt the same?  What a sorry world this would be.
Okay - If your drawings always use the same combination of lines and curves, positive and negative relationships, or lack insight into the real world, you will bore your audience to death.  Boring drawings will never get top dollar.