You can only check-In or upload your code into the TFS cloud repository using Visual Studio or Eclipse. You can also manage work items and bugs using Visual Studio. Online TFS would store your source code and work items in the cloud.
Like github and other online repository solution, you can also make your project repository on TFS at http://tfs.visualstudio.com/. Now online TFS allows you to plan your projects, collaborate with your team, and manage your code online from anywhere.
TFS stands for Team Foundation Server which is developed by Microsoft. Integration of TFS with Visual Studio enables a team to work together and organize their efforts to complete a project. Dot Net developers use TFS for source control, bug tracking, requirement gathering and to manage complete life cycle of software development.