IE is retiring and transitioning over to Microsoft Edge.
Retiring Internet Explorer
Microsoft is transitioning Internet Explorer to Edge.
Internet Explorer itself is retiring and being replaced by Edge.
Edge is a completely new build that is built for today's modern web experience.
Edge is much smoother and less resource intensive.
Edge has the Chrome engine which is 100% compatible with Google Chrome feature-set.
Edge also has backwards compatibility built-in to help with transitioning older Websites and Apps.
Sync within Edge now works smoother with your M365 Sign-in, actually quite impressive and using multiple devices now feel more like ONE.
This transition from IE is taking place now(any desktop managed by LoneSync was transitioned a while back).
M365 will no longer support Internet Explorer past mid-June.
If you are using IE and do not see the option to update, proceed to (microsoftedge.com) to download.
As always running the latest updates overall keep you safe and less prone to interruptions with changes.