Originally announced in Apple WWDC event in June month, Apple is set to push final version of its upcoming iOS 14 and iPadOS 14 to its devices starting today.
iOS 14 compatibility: It will be available for iPhone 6s and later models.
iPadOS 14 compatibility: It will be available for iPad Air 2 and Later, all iPad Pro models, iPad 5th Generation and later and iPad mini 4 and later.
The list of all features to be introduced in iOS 14 and iPadOS 14 can be found in below links
Alongside iOS14 and iPadOS 14, compnay will also start pushing watchOS 7, and tvOS 14 later today