It depends on the product compared to the reactant. If you end up with a pair of carbonyls, then you've gained oxygen in place of what used to be bonds to C. There aren't too many other ways to cleave a double bond besides oxidative cleavage, but the reactions of alkenes are not tested, so those other specialty reactions are not relevant. Because oxidation is a testable topic, oxidative cleavage of a double bond is worth knowing in general.
One way to oxidatively cleave an alkene is with KMnO4. The result in basic solution is a glycol. In acid, the result is a carboxylic acid. Either way, as BerkReviewTeach said, you've gained oxygen bonds which as a rule of thumb is oxidation.
I use "HLOG" Hydrogen Loss/Oxygen Gain is oxidation and "HGOL" Hydrogen Gain Oxygen Loss is reduction to keep the products of those reactions straight. I don't have a way to connect each acronym to oxid or reduc yet but eventually I'll try to come up with a phrase.