Nintendo has released a new update for the Switch, although it doesn't appear to change a whole lot. Update 6.2.0's patch notes simply state the new version includes "general system stability improvements to enhance the user's experience."
The update is not mandatory, so you may need to manually download it. To do so, go to your System Settings and scroll to System. From there, you can select System Update to trigger the download. This latest patch is only a minor one, following on from September's bigger update that finally introduced Nintendo Switch Online.
Nintendo's online subscription includes a bunch of NES games at no extra cost, as well as the ability to back up all your save data to the cloud. Memberships can be purchased for one, three, and 12-month increments for $4 / £3.50, $8 / £7, and $20 / £18 respectively.