Once you have a project linked to an online version, you can sync the project. Syncing allows users to upload any changes they have made to the project on their local branch with the online version. If there are multiple users working on the same project, this allows collaboration, where each user can gain access to changes made by the other users.
Syncing a project does two things:
Download latest changes: The first step of the sync is to update your local project with changes made to the online version. Assuming this is successful, your project is updated with any changes made to the online project by other users.
Upload your changes: The second step of the sync is to upload your local changes to the online version of the project. This will allow other users to download your changes and have them applied to their local project versions.
Occaisionally when syncing projects, a merge conflict will occur. A merge conflict is when the same file or group of files has been modified by multiple users. The Portal will try its best to resolve merge conflicts without your help, but this will often fail. For help resolving merge conflicts see here.