As a reminder, the Raspberry Pi default firmware has adopted Linux 4.0 as default two months ago, and now Kernel 4.1 has been implemented, being the most advanced stable kernel released.

Keeping an up to date Kernel on a Linux system is very important, due to the fact that each new version brings architecture fixes, file system enhancements and support for new hardware components.
To receive Kernel 4.1 on your Raspberry Pi system using either Raspbian or Ubuntu MATE, just open a terminal, update the local repository index and trigger a regular system upgrade:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
If you don’t know, Raspberry Pi is a credit card sized ARM singleboard computer, being used a lot by FOSS enthusiasts to power their DIY projects.