Judging by what I see online, most Americans have no idea how Israeli elections actually work. Here's a short introduction.
Nobody votes for prime minister. Israeli voters cast their ballots for one of many political parties. The parties get a share of the 120 seats in the Knesset in rough proportion to the number of votes they actually got. (You have to get a few percent to get ANY seats at all.)
The party that gets the most seats in the Knesset is usually--but not always--the one that gets to try to form a coalition with some of the other parties that includes more than 60 votes out of the 120. If they do, the leader of that party becomes the prime minister. So, neither Netanyahu, Herzog, nor anybody else was elected as prime minister today.
No party is clearly ahead. Depending on which poll you trust, either the two biggest parties have 27 seats each or the Likud has 28 and the Zionist Union has 27. It's basically a draw.
Therefore, it's not clear who will be asked to form the next government. That's up to the President of Israel (not the Prime Minister), and he has stated a clear preference for a "government of national unity": that is, a government that includes BOTH the biggest parties and others besides.
Netanyahu's party, the Likud, may have an advantage. It's fairly easy to see how they would get to 60+ votes. If every right or center-right party supported them, they'd be in.
But maybe not. One of the center-right parties is a breakaway from the Likud, headed by a man who personally dislikes Netanyahu. That party might choose to ally with center-left Zionist Union instead...for the right price.
The biggest news is not who's #1 nor #2. The third largest bloc in the Knesset is likely to be the Joint List of Arab parties and one Arab & Jewish party. That has never happened before. What it means for the future is unclear, but at the very least, they'll be in a position to lobby for better services to Israeli citizens who are Arabs.