I saw this for Delta cards. Are there more category of miles?
SkyMiles are RDMs, i.e. miles you redeem for airfare, when someone says miles, they're probably referring to these. Medallion "miles" are EQMs and are used to calculate how many miles you've flown/earned toward elite status. These "miles" cannot be redeemed for airfare and are only relevant to you if you're trying to attain elite status.
