In order to reveal differences in content, users can compare Value Sets or Value Set releases.
Users have two options for starting a comparison: either from the Releases tab, or using the dedicated button in the top-right corner of a Value Set page.

From the Releases Tab

Pressing the
button displayed next to a release will run a comparison between the selected version and the next available version.
In case of only one avilable release, the comparison will be run between the selected version and the unversioned state of the Value Set.

From the Value Set's page

Pressing the
button displayed in the top-right corner of the Value Set's page will invoke the Compare wizard.
Value Set Compare Wizard
You can select which versions you would like to compare using the dropdowns.
Once the versions are specified, pressing the
button will calculate the changes and display the results accordingly.
To compare different Value Sets, simply click in the bottom field and select another Value Set from the dropdown.

Compare Results

Differences are checked and calculated on two levels: members and clauses.
The section on the left-hand side collects the changes detected in the member list, while the right-hand side section displays the differences in the clause list.
Matching content will not be displayed, only the number of unchanged members and/or clauses will be indicated.
Both the member and the clause list headers display statistics related to the comparison. Besides displaying the number of members and clauses present in the different versions or Value Sets, the number of changes is also indicated.
Value Set Compare Results
You can always modify the settings - e.g. by selecting other versions, or even two different Value Sets -, and run a new comparison using the

Understanding the results

The comparison always has a direction, which is represented by the arrow between the selected resources base
The member or clause is present in the base Value Set, but it is NOT present in, i.e. is removed from the target Value Set.
The member or clause is NOT present in the base Value Set, but it is present in, i.e. is added to the target Value Set.