如何在SQL Server中实现内部和左右外部联接？

I'm looking for a high-level, algorithmic understanding so that I can get a Big-O sense of what SQL-Server is doing to perform joins. Feel free to be concise, I'm not looking for the extremely nitty gritty. The thing that prompted me to understand how joins are implemented better is the scenario behind I'm looking for a high-level, algorithmic under