In the Wiki, files can be uploaded, stored, and distributed to viewers and visitors.  They can be displayed as clickable thumbnails but for efficiently efficiency they are better presented as links.  When clicked, many file types appear in a viewer, where visitors can read or view text, tables, images, and other illustrations, and scroll between pages.  If visitors have access to a file in Confluence, they can download a copy of it to their device.

Here is an example of a file stored by the wiki.  You can see this sample PDF in a viewer by clicking the link:

test&demo COLI.pdf    This is a crude link that displays the file name.

A Demonstrator File  This is a hyperlink that goes to the same file as above, but has a nicer link text that looks a bit more professional.

Files as Attachments

Files stored in the Wiki are attached to particular pages.  You, and any visitors, can see all the files attached to a page by visiting the attachments page, by clicking the righthand menu icon, and choosing Attachments.  At a glance, the number after the link in the righthand Attachments link will show you how many files are attached to this page.

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The Wiki may not be the optimal location for shared files.  The wiki can "host" or house files for distribution to visitors.  But for certain applications, it may not be ideal.  For example, if you only need to periodically share files within a committee, and you neither need a set of hierarchical web pages, nor to share the files with the general public, then a Google Drive shared folder or team drive might be more efficient.  

Images displayed on a page are attached files.  If you go to the Attachments page for this wiki page, you will see the image displayed above listed as files named "wikiattach.jpg" and "wikiattach2.jpg."