.htm vs .html what is different?

html

The .htm and .html file extensions are used for HTML files, which contain Hypertext Markup Language code that is used to structure and format web pages. Both extensions are used to identify HTML files, but there is no functional difference between them.

In the past, the .htm extension was more commonly used for HTML files on Windows systems, while the .html extension was more commonly used on Unix and Linux systems. However, with the widespread adoption of modern web browsers and operating systems, the use of the .htm extension has become less common, and the .html extension is now the more widely used and recognized extension for HTML files.

There is no requirement to use one extension or the other, and you can use either .htm or .html for your HTML files. Both extensions are recognized by web browsers and will be treated the same way.

For more information on HTML and the use of the .htm and .html file extensions, you can refer to the HTML documentation: https://developer.mozilla.org/en-US/docs/Web/HTML.