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.
A file with .emz extension is a compressed container of Enhanced Metafile (.emf file). It follows GZIP compression algorithm and takes less storage space due to compression. The small file size makes it more easy to transfer EMZ files over the network.
You can also convert AI into many other file formats. Please see the complete list below.