What is the main difference between Interest, Usury and Riba?

Native language speakers say that in English Interest is a nominal charge on the principal amount lent. Usury is an exploitative high charge on the principal.

Riba on the other hand includes both Interest and Usury along with a host of other transactions like we have discussed whist explaining Riba al Fadl and Riba An Nasia

Hope the distinction is clear to you.