It provides some additional features, which are not possible with server-only forge mods: (Note: The client addon is functional compatible with the server side mod and is thus only updated when there is a change on the client side)
For the most part you do not need to update the client. We now have automatic deployments that keep both mods in sync but older versions will continue to function without issues on newer versions of FE.
For more information about the ForgeEssentials project, visit our main CurseForge page.
PLEASE DO NOT POST ISSUES HERE, BUT ON THE ISSUE TRACKER ON GITHUB INSTEAD!