Help:Files
Files have a binary, such as an image, and a description page in the File namespace. Follow Project:Image use policy and Project:Copyrights before uploading or replacing media.
Upload and describe
Use Special:Upload if your account has permission. Choose a descriptive filename and record the creator, actual source and applicable licence or permission. Distinguish screenshots, concept artwork and historical versions. Another website hosting a file is not proof that you may reuse it.
Use an image
An article can display a thumbnail with a caption and alternative text:
[[File:Example.png|thumb|alt=Brief description for readers who cannot see the image|Caption explaining its relevance.]]
Replace the example filename with a real local file. To link its description without displaying it, use [[:File:Example.png]].
Replace or remove
Check the file's usage and description before uploading a replacement. Preserve relevant credits, licences and history. A replacement should still illustrate the subject expected by existing articles. Remove an image from an article when it is inappropriate there; deleting the binary is a separate administrative action. Use Project:Files for discussion for a disputed file and Help:Options to hide an image for a reader-side concern.