JPEG .jpg is common on the internet. Displays thousands or millions of colors. Very common, variable compression scheme. Depending on saving, compression reduces quality of image. GIF .gif is very common on the internet.
Advantages are small file size.
Disadvantage is that image only displays 256 colors. Tiff format however has no loss in quality and is used by many programs. Used for saving file for printing. BMP .bmp is the standard Windows image format. File size is large like TIFF and is rarely used on Macintosh computers.