What is the difference between dynamic programming and greedy approach?

Question

What is the main difference between dynamic programming and greedy approach in terms of usage?

As far as I understood, the greedy approach sometimes gives a

Answer 1

I would like to cite a paragraph which describes the major difference between greedy algorithms and dynamic programming algorithms stated in the book Introduction to Algorithms (3rd edition) by Cormen, Chapter 15.3, page 381:

One major difference between greedy algorithms and dynamic programming is that instead of first finding optimal solutions to subproblems and then making an informed choice, greedy algorithms first make a greedy choice, the choice that looks best at the time, and then solve a resulting subproblem, without bothering to solve all possible related smaller subproblems.