"Variations," sometimes also known as "running changes," are changes made to a toy through its production cycle. Some changes are intentional (so a company can offer you a different product) and are often referred to as a "variation." An example would be a toy that employs one mold that's painted numerous ways in order to provide a complete army. Variations are sometimes but not always created with the collector in mind.
"Running changes" are alterations made to a toy due to available materials, aesthetics, marketing, or safety concerns. An example is the short and long lightsaber issue from 1996 or revising packaging to have the most up-to-date figures on the back of the package. While these toys with running changes are not usually intended to be collectibles, they often become them.
At Entertainment Earth, we ship you the toys we receive right from the manufacturer. So, you receive the same figures we do. Whether it's a common version or a special rare treat, you're not charged a premium for an assortment containing a special toy or collectible.