HTM, Hypertext Markup Language File (.htm)
The HTM Website file format
Any HTM file contains web based markup code that the web browsers use to display and format text as well as images. The HTM file format serves the exact same purpose as an HTML file, and in the present day there is no difference between the two.
Technical details of HTM files
A HTM file is a markup based file that uses various markup tags and codes to utilize a web browser to display information in a formatted format. This allows web designers and developers to create structured pages and ad desired effects to the page.