What is a 'callous'?

What is a 'callous'?

A callous is a very hard, dry skin that builds up on the foot. When we are wearing shoes, we are applying more weight on one side of our foot than the other, so once you're walking in that spot over and over and over again, it's building up almost like a defence part. It's building up because you're applying all that pressure, so you need to be careful because we want to remove the callus, but we don't want to take too much off, because if you take too much off then it becomes very painful. It's there for a reason.