Note: The publishing feature requires a site to be open. The site must specify both a local and remote root path.
If you are working with a local mirror of files from your web server, the publishing feature allows you to track and upload just the files that you have changed locally.
First, make sure you have specified local and remote root paths for the site which represent equivalent file hierarchies.
Coda marks changed local files with an "up arrow" icon.
Clicking this icon will upload just that file to its equivalent place in the remote file tree.
You can upload all changed files in one shot using the Publish All button that appears at the bottom of the file browser after you've changed local files.
If you prefer to work remotely, directly editing files on your web server, publishing isn't necessary, as your files will be uploaded as you save them.