Microsoft recently released its semi-annual major update to the Windows 10 operating system. This one is known as Feature Update 1909 and it adds a number of new "features" for you to check out. This update installs much faster than previous spring & fall releases but it will require a restart of your PC. At least for now, FU 1909 is an optional update and requires that you navigate to the Update & Security setting and click on the "download and install now" link.
You can check your current version of Window 10 by right-clicking on the Start button and clicking on System (the gear icon). You should see something similar to this: