Microsoft Office 2019 Home & Business currently retails for $249 for a single PC license. Microsoft Office licenses are the gold standard of office applications, but they cost a fortune. If you don't need or have access to the full might of the desktop version of Microsoft Office, you can use the free online version instead.
Besides being available for PC and Mac, Office is available in Home and Student and Home and Business Editions.
Older versions of Microsoft Office still available and supported by Microsoft go back as far as 2010, but the most popular pre-2019 version of Office is Office 2016.