MACROMEDIA FREEHAND 10-USING FREEHAND Use Manual page 426

GIF, JPEG, and PNG graphic file formats are commonly used for the Web
because they can be highly compressed for faster transfer across the Internet and
because they are supported by most browsers. (Note that the GIF and JPEG
formats are more widely supported than the PNG format.)
You choose a Web image file format based on the color and graphic qualities of the
original image, as outlined in the table below. When preparing graphics for the
Web, remember to preview the compressed images in a browser to ensure that
images will appear as intended.