The new version of Raspberry Pi OS comes a little over two months after the previous one and it’s the first to finally bump the kernel version from Linux 5.10 LTS to Linux 5.15 LTS in an attempt to provide users with some new features that weren’t present in the previous kernel series.
Linux kernel 5.15.30 is included by default in the new Raspberry Pi OS release, though you should know that Linux 5.15 will only be supported until October 2023 while Linux kernel 5.10 LTS will be supported until December 2026.