A short kit is where all the wood that needs to be cut out (i.e. bulkheads, ribs, etc) is done. All the sheet stock, stick stock, etc. has to be bought from another source. I've seen some short kits come with molded parts like cowling and canopies, and even some with formed landing gear, but you'll have to verify on an individual basis what the kit comes with.

Hogflyer