(As the joke goes "Can a cousin, once removed, be returned? The short answer is "No, they're not the same thing." Let's take a look at what those cousin terms mean and how you can figure them out in your family tree.
There are far too many "greats" there for it to matter.
In the general sense, cousins are two or more generations away from any common ancestor, thus distinguishing a cousin from an ancestor, descendant, sibling, aunt, uncle, niece, or nephew.
However, in common parlance, "cousins" typically refers to "first cousins" as the children of one's uncles and aunts.
The further back the first common ancestor is, the larger the number.
First cousins are as close as you can be and still be cousins.