Considering buying a MacBook Air with M1 porcessor. Is Microsoft Office compatible with M

Office 2019 and Microsoft 365 will run on the M1 Macs with Rosetta 2 emulation (and run well). Microsoft has a beta version with native support, if you're adventurous. Either way, yes you can run Office on a new M1 Mac.

It's how software written for Intel Macs can run on M1 Macs. It's behind the scenes.

Microsoft has released an Office Suite specifically for the M1 processors as of December 15th.