Extremism lexicon question

I'm sure most of us know about the Department of Homeland Security extremism lexicon, correct? Well, I have a quick question about it. Does the lexicon define what the Department of Homeland Security considers terrorism or just extremism? I always though it was terrorism, but I might be wrong. Thanks for the help.

You can find the lexicon here if you need it: video1.washingtontimes.com...