I'm happy to be helpful! I definitely remember when I was new here (and to crypto) where I'd read updates and not feel I understood.

Think of hard forks as updates that change the rules of the blockchain...though they don't always end up splitting the currency like it did with Bitcoin and Bitcoin Cash. So in the case of Steem, changing how voting works (like changing the 30 minute penalty to 15 minutes), whether rewards are scaling versus linear (a change made months back, etc require a hard fork. However, before a hard fork is enacted, the witnesses have to vote and have consensus on whether to implement it.