Meaning of VARIATION in English
var ‧ i ‧ a ‧ tion W2 AC /ˌveəriˈeɪʃ ə n $ ˌver-/ BrE AmE noun
[ Word Family: noun : ↑ variable , ↑ variance , ↑ variant , ↑ variety , ↑ variability , ↑ variation ; adjective : ↑ variable ≠ ↑ invariable , ↑ varied , ↑ various ; adverb : ↑ variably ≠ ↑ invariably , ↑ variously ; verb : ↑ vary ]
1 . [uncountable and countable] a difference between similar things, or a change from the usual amount or form of something
White bread is really just a variation of French bread.
variations in the quality of the rugs
There is a great deal of variation among the responses.
The study concluded that the variation between the CD players was very small.
2 . [countable] something that is done in a way that is different from the way it is usually done:
Most of his poems are variations on the theme of love.
3 . [countable] one of a set of short pieces of music, each based on the same simple tune:
Bach’s Goldberg variations
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012