I was working with my home laptop this morning and this message popped up in the lower right of my screen. This is Microsoft giving you time to update your computer. Microsoft will no longer support Windows 10 1803. What is 1803? This is a build version. Windows will always be called Windows 10 at this point but there will always be updated builds.
So how do you see which build or version you have on your computer? Right-click on your start button and left-click on system.
Once the System panel opens up scroll down and look for Windows Specs and you will see the version.
If you are using 1803 or anything earlier I would suggest you update your computer now. Always make sure you keep up on the updates to ensure you are always getting the current security updates.