Context ribbons are ribbons which appear only for specific grids, worksheets or features. The context ribbon will show only when those features or functions are active, and where they are available for the user / role.
The Line Tools Definition ribbon (above) is an example of a context ribbon. The ribbon allows users to manage Lines Definition features and will only appear when a Line Definition is open.
You must have the appropriate rights to maintain building blocks for the ribbon options to be active and available for selection.