Check one of the choices to choose an output format:

single

This returns a list of matched the tunes. You can click on a single link, which returns the tune in one of the supported output formats.

multiple

This lets you select several tunes and several output formats. You then click on the "Get" button, which collects all the tunes into a single ABC file, converts it to all the selected output formats, and returns a table of links to the resulting files. A few of the formats (GIF,PNG) are also returned inside the HTML page, so you can see them immediately.