what does the tier system mean?

The tier systems, contrary to popular belief, mean almost nothing. My fav frats are AEPi, Pilam, and TEP, and even though they aren't "top-tier" I personally had more fun at their parties and gamedays than the top frat houses. My best friend is currently dating a pikapp, and he's awesome. There are cool and attractive guys in every fraternity, and while some obviously have more than others you shouldn't just cherry-pick the "top frats." I personally don't like SAE/ATO at all and I'm not a fan of pike either after a bad personal experience at one of their socials with my sorority. It's just a personal preference. Find guys that you get along with personality-wise, there will always be cute guys in every frat.

To put it easy, it is an indicator of social calendar. Top sororities have socials with top fraternities, etc, etc. HOWEVER, i've seen plenty of girls & guys from different tiers hang out with each other. Even if you're in a bottom tier sorority, you can still go to top frat parties. You can still take them on date functions/formals and vice versa. It is literally just for socials & homecoming. Most people literally could care less about what sorority/fraternity you're in, especially with rush getting more competitive by the year. While the poster above is slightly correct, not EVERY bottom girl is socially awkward and not EVERY top girl is popular.

I hope that helped!!!

This was a good question! Good luck!