Cousins, non-identical cousins...

OK, Heather, since you asked...

First, an Explanation of cousin numbers. The children of siblings are 1st cousins to each other. The 1st comes from the facts that each child is ONE generation removed from one of the original pair of siblings.

Example:
A & B are siblings. Each has a child. A is the parent of C and B is the parent of D. C is one generation (or step or degree, to use Kevin Bacon terminology) removed from A and D is one generation removed from B.

Suppose C is the parent of G and D is the parent of H. G and H are each TWO generations (degrees, steps) removed from the original siblings, A & B. Thus, they are 2nd cousins to each other.

How is C related to H? C is one generation removed from sibling A. H is two generations removed from B. You take the shorter number at the type of cousins, and take the difference between them as a degree of removal. 2-1=1. Thus, C and H are 1st cousins (C's distance from A), once removed.

Clear?

Now to my family (real names used only for the deceased)

1. PW & DD are children of my Dad's half sister, SuzieQ. We (me & PW & DD) are each one generation removed from the siblings, my Dad & SQ. One degree equals ... we are 1st cousins (1C) to each other. That's easy enough.

Now it gets complicated...

2. My paternal Aunt SQ adopted her 1st cousin Bt when Bt's mother died. Bt and my Dad were also 1st cousins, so, before he became my 1st cousin through adoption, Bt was originally my 1st cousin once-removed. The sibling pair were my paternal grandmother Ermal (2 degrees removed from me) and Bt's mom Roseanna (1 degree removed from Bt.) Bt's brothers and sister include PW & DD. It would stand to reason that the siblings of my 1st cousin once-removed were also my 1st cousins once-removed (1C1R).

3. (Maybe easier than #2.) Remember that SQ is my Dad's half-sister? Her father, my Dad's step-father Bob, was the 1st cousin of my Dad's father, James. Yes, my grandmother Ermal married two men, James and Bob, who were 1st cousins to each other. Counting back 2 generations to the sibling pair (Bob's father and James' mother), my Dad and his half-siblings were 2nd cousins to each other. Going forward one generation to me and to PW & DD, you find that we are 3rd cousins (3C) to each other, based on our great-grandparent's having been siblings.

PW's son Zk (one generation removed from his Dad) is my 1C1R, 1C2R, & 3C1R. He is the 2C, 2C1R, and 4C of my assorted nieces & nephews.

Clear? Could be weirder...
Izzy's family has the situation in which two siblings married two siblings (2 Koniecsko's married 2 Gosiks) and thus their children were double 1st cousins.

Wikipedia's chart looks like it's on steroids...