Because CSUN is mainly a commuter school, students often don't get the social atmosphere they would at other universities with more housing options. Thus, getting involved with Greek life is an alternative if you want to feel a sense of unity. Greeks are everywhere, but not so much that they are in your face about it. Of course, rush period can make it seem like Greek life dominates, but other than that, fraternities and sororities don't really stand out all that much. They mostly just participate in fundraisers.
Just as CSUN is diverse in its population, it's also diverse when it comes to the different Greek organizations that are offered. Everything from Christian to Armenian Greek organizations are available for students to join, representing multiple cultures. However, students don't have to go Greek in order to have a social life; it's just easier to have one if they do.