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 WMF extension represent Microsoft Windows Metafile (WMF) for storing vector as well as bitmap-format images data. To be more accurate, WMF belongs to the vector file format category of Graphics file formats that is device independent. Windows Graphical Device Interface (GDI) uses the functions stored in a WMF file to display an image on the screen.
You can also convert AI into many other file formats. Please see the complete list below.