A file with an .ai extension is an Adobe Illustrator Artwork file that contains vector graphics on a single page. It uses points to create paths for displaying the image data, thus making it safe from losing image quality if it is enlarged. AI format finds its major usage for logos and print media. AI files can be opened with Adobe Illustrator, Adobe Acrobat DC, PaintShop Pro, and CorelDraw Graphics tools.
Files with .htm extension represent Hypertext Markup Language for creating web pages for display in web browsers such as Google Chrome, Internet Explorer, Firefox, and a number of others.
You can also convert AI into many other file formats. Please see the complete list below.