Force.com IDE Developer Guide

Get Started with the Force.com IDE
Develop with the Force.com IDE
Force.com Project Basics
Apex Code in the Force.com IDE
Lightning Components in the Force.com IDE
Server Synchronization
Save to Server
Refresh from Server
Synchronize with Server
Test Code with the Force.com IDE
Deploy Code with the Force.com IDE
Get Started with the Apex Debugger
Solutions to Common Force.com IDE Problems
Force.com IDE Release Notes
Useful References
PDF

Server Synchronization

When you create a Force.com project, the files you specify in your project manifest are copied from the server (your Salesforce organization) and stored locally on your computer.

The term project refers to the local files on your computer, while the term server refers to the live metadata components in a Salesforce organization.

Note

As you develop in the IDE and make changes to the metadata files in your project, it is possible that you (or another developer or administrator) may make changes to the metadata components directly in the browser from the Salesforce Setup menu. Or if you are working in a team-based development environment, other developers may make changes in the source files in your shared repository. In either case, when metadata is changed outside your project, your project is not immediately aware of those changes and your files may get out of sync.
There are three actions you can take to keep your project and organization files in sync. All of these actions are available by right-clicking the project src folder and choosing Force.com:

If you receive a save error that updates only your local instance (your local project or source control repository), this indicates that your files are not in sync with the server. To replace project files with server definitions, use Refresh from Server. To push project files to the server, use Save to Server.

Note