Nuget consolidate vs update

In NuGet for Visual Studio 2015, what is the difference between consolidate and update actions? In both cases I select a specific version that I want to use in selected projects.

What does NuGet consolidate do?

Consolidating NuGet Packages If there are different versions of a NuGet package installed in the solution the Consolidate tab will show this and allow the packages to be consolidated to a particular version. When a NuGet package is selected, the right hand side of the dialog shows all the projects in the solution.

How do I clean and restore a NuGet package?

Restore packages manually using Visual StudioEnable package restore by choosing Tools > Options > NuGet Package Manager. Under Package Restore options, select Allow NuGet to download missing packages. In Solution Explorer, right click the solution and select Restore NuGet Packages.

The Update tab is geared to display packages which have updates available while the consolidation tab is geared to display discrepancies between projects where both consume the same nuget package but are targeting different versions.