Please "explain to me like I'm 5" Palestine vs Israel

K....here's the thing. I don't want to sound like a total n00b by asking this, but I will, so there's no way around it.

Please explain to me in simple terms so I can get the jist of what exactly is going on these last few months, and why??

Something that I find interesting about this conflict and it's influence on social media, is that both sides appear to be supported equally in amount. I see some people cheering on Palestine and I see some people cheering on Israel.

I want to understand. Thanks