How to check Kernel Version

$ uname --help
  -r, --kernel-release     print the kernel release

$ uname -r
5.4.0-65-generic
$

$ uname -a
  -a, --all                print all information, in the following order,
                             except omit -p and -i if unknown:

$ uname -a
Linux conoha-ubuntu20 5.4.0-65-generic #73-Ubuntu SMP Mon Jan 18 17:25:17 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
$

$ cat /proc/version
Linux version 5.4.0-65-generic (buildd@lcy01-amd64-018) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #73-Ubuntu SMP Mon Jan 18 17:25:17 UTC 2021
$

$ ls /lib/modules
5.4.0-42-generic  5.4.0-66-generic  5.4.0-70-generic  5.4.0-72-generic  5.4.0-74-generic
5.4.0-65-generic  5.4.0-67-generic  5.4.0-71-generic  5.4.0-73-generic  5.4.0-77-generic
$

linux#kernle