When viewing a set of search results (either as a result of issuing a query, or by accessing the Documents Saved workspace for a given task), a list of keywords are provided at the top of the page. These keywords are extracted automatically from the list of documents being shown, and therefore will change for different queries, different sets of search results, and different workspaces.
If you identify a keyword that is of specific interest for your search task, you can click on it to highlight it. Doing so adds a colour code to it; any documents in the search results list or workspace group that match this keyword are highlighted with the same colour code in a series of small blocks across the top of each search result. The order of these blocks matches the order in which the keywords were selected. This allows you to quickly scroll through a set of search results and visually identify which are using the keywords you have highlighted. If you find that a selected keyword is not of interest anymore, it can be removed from the highlight list by clicking on the garbage icon beside it.
For a given search task, the selected keywords that are used to highlight the search results are preserved between queries, as you move through the pages of the search results, and when viewing the workspace. These selections are also preserved between search sessions, allowing you to easily resume your search activities at a later date.