What are Master Resale Rights?
Master Resale Rights gives you the opportunity to sell both the product AND the resell rights. This increases value of the product significantly, because your customer may resell the product for profit too. You own the software completely.

What are Private Label Rights?
Private label rights allow you to make another author’s work show like it’s yours by changing its content. That can vary from writing an introduction paragraph or editing the title to completely modifying it any way you want and add your name to it as the creator (with or without the condition that you HAVE to modify the content). Anything allowing you to change the content (except branding an affiliate link) is called Private Label Rights.

What are Resell or (Resale) Rights?
Resell Rights work the same as Master Resale Rights, with the exception that you may sell the product and keep 100% of the profits, but you may not sell the resale rights to your customers, meaning that they are not allowed to resell it!