I have been taught by my professor that the topological sort gives a total ordering of a partial order. However, I do not see how this is the case. You are simply rearranging the elements in the partial order set in the topological sort, so how does that convert a poset to a total order?
This link supports what my professor says. link
At its core, a topological sort, or a linear extension, is a total ordering of a partially ordered set.