Every 6 months, Fedora releases a new version of the operating system. This is typically at the end of April and October of every year, though this is not a strict timeline.
In other typical operating systems, upgrading to a new version means upgrading all your system packages, however, this is not the case with Fedora Silverblue. To upgrade to a new version of Silverblue a user has to change the image stream that your operating system is pulling from.
Below are very articulate instructions for doing this in Silverblue.