With the release of the first iOS 11 developer beta last week at WWDC 2017 and the second beta of iOS 11 recently, Apple now launches public betas of iOS 11 and tvOS 11.
iOS 11 is the major upgrade for Apple and has included number features and changes in it.
iOS 11 beta 2 contains bug fixes and improvements. Apple bought a number of features and fixes some bugs in this public iOS 11 beta. See its release notes
Along with iOS 11 public beta, Apple launches tvOS 11, macOS High Sierra Public Beta 1 to public.
iOS 11 Public Beta is available for download on iPhone – iPad and iPod touch via OTA over-the-air from iOS settings app through Apple Beta Software Program. Similarly, for Apple TV, tvOS 11 Public beta 1 can be installed in Settings → System → Software Updates → Update Software.
To get iOS 11 Public beta you need to download the configuration profile and install it from the OTA Software.