After the design and construction phase, an application or a new operating system goes through several stages until it is installed on the devices of all users.
Regarding watchOS, iOS, iPadOS, tvOS yes macOS, two of these steps are:
1. Apple Developer Program (Developer Beta), in which application developers can create, optimize and test applications for the future operating system.
2. Apple Beta Software Program (Public Beta), in which all users who want to test and discover the new features of the future operating system can register.
The future iOS 15 / iPadOS 15 was presented on June 7 at WWDC21, and immediately after the end of the event, the first beta version was made available to the developers.
When will iOS 15 be released and iPadOS 15 Public Beta?
Release date of the first Public Beta version for iOS 15 and iPadOS 15 has not been announced yet Apple, but it will most likely happen at towards the end of June, if it is to take after the release dates of previous beta versions of iOS 14 si iOS 13.
The first version Public Beta in iOS 14 was officially launched on July 9 2020, after it was first presented at WWDC20, in period June 22-26. The event was usually held in June, but the pandemic forced it Apple to postpone it and to carry it out in special conditions.
If it is to make a pertinent estimate from the previous data, there are high chances that iOS 15 Public Beta to be released towards the end of June 2021 or at the latest at early July.iOS 15 Public Beta Software Program