How Do I Explain the Houston LiveStock Show & Rodeo?

I haven't been to the Rodeo in years except a concert here and there. Now a friend who recently moved to Houston wants to check it out for the first time and was asking about it, including what activities would be good for small kids. I felt so lost and as a native Houstonian a little blushed at not knowing how to answer (besides she should dress up her kids for Go Texan Day because that was always fun as a kid). Please help. How do I explain the Rodeo? What should we check out? And what activities are good for small kids.