Difference between Status.FAILURE and Status.ERROR

Hello!

What is the difference between jetbrains.buildServer.messages.Status.FAILURE and Status.ERROR?  I checked two situations and in both cases  jetbrains.buildServer.serverSide.SBuild.getBuildStatus returns Status.FAILURE:

1. Build failed to start because VCS root is unreachable.
2. Build failed because build script has exit code 1.

My task is to show custom BuildTab only for failed builds and I currently use Status.isFailed() which  returns true both for FAILURE and ERROR if I understand right.