Yeah, I can see how you would call that a steering joint, since that's what allows things to turn, but since they're in the axles, and there are also u-joints in the steering shaft itself, like StnePny said, it's easier to differentiate that way.
Looks pretty rough in there too aklb. You're probably going to find out that you need a new spindle bearing as well. if you're lucky, yours will be ok, but with all that rust and ugliness behind there, looks like water was up-close-and-personal with your components.
At least having to take it all apart, right down to the spindle, will give you the chance to do some (usually) much needed maintenance and check your wheel bearings and such.
Good luck.
Oh, and since you've got it so far apart, I would just bite the bullet and change out all four ball joints at the same time. It'll add substantially to the cost, but it sure beats taking it all apart again sooner than you'd like.
Have fun!
Paul