What exactly does "final order of deportation" mean?

I have a cousin who came when he was a baby but recently he had to go back to mexico for an emergency but when he came back he was ill advised and went through the port of entry without anything thinking he could talk his way through (I scolded him for it, believe me)

But he got caught and even though they felt bad for him cause he told them his story he sent back to tijuana and I think they gave him a 3 year bar from entering the country, but he did make it back using I think someone's passport that looks like him. He's never jumped the border though, everytime, including when he was a baby they brought him through the port of entry.
I was gonna see him soon and I wanted to find out for him. thanks