Pruning nodes are described in the sourcecode thusly:

-prune=<n>: Reduce storage requirements by pruning (deleting) old blocks. This mode is incompatible with -txindex and -rescan.

I’ve watched that my node has been consistently uploading less than it has been downloading since I set it to run in pruning mode.

• What services do pruning nodes still perform?
• Do they upload blocks and transactions?
• Can they service thin clients?
• What can a pruning node not do, that a non-pruning node does?