When off-trail routes are described, you’ll often see “go down a scree field” or “make your way through a talus slope. “
So what the heck is talus? What the heck is scree? And what the heck is the difference???
Technically there is no difference.
However, most people, myself included, make a distinction between the two in outdoor circles. As has been the case for over two-hundred years.
Scree is loose. Generally small sized rocks. I’d say up to a ping-pong ball or so in size at the most:
Talus is generally larger and can be loose or not:
As with the YDS classes, there is some gray area between what is scree and what is talus. And you’ll often find them gradually mixing into each other, too.
Overall summary: Scree is loose and small; talus is larger and not nearly as loose as scree. You can often go boulder hopping with talus. You can “ski” a scree field.