A Variant, as we define it here on hobbyDB, is an item that is similar to another, but collectors have no problems seeing the difference (as opposed to Subvariants, which are similar enough that you have to look close to see the difference). Most of the time manufacturers regard variants as separate products. 

A few examples of Variants would be...

Volunteer Squad members with Contributor access or above can help improve hobbyDB by connecting items as variants (how-to article here). If you're interested in getting involved, read more about joining the Squad here. We'd love to have you aboard!

Short video explaining the difference between Variants and Subvariants: