Ubuntu Server 18.04 LTS - What kernel version does it come with? [duplicate]
The same kernel. It's the same distribution.
The only difference between the server media and the desktop media is the installer, and the default set of packages. The repositories and software versions is identical.
From Ubuntu Server FAQ:
Before 12.04, Ubuntu server installs a server-optimized kernel by default. Since 12.04, there is no difference in kernel between Ubuntu Desktop and Ubuntu Server since linux-image-server is merged into linux-image-generic
https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes#Linux_kernel_4.15 specifies it comes with the 4.15 kernel.