What is the difference between these 2 pedals? They are both Shimano 105's but 1 set is a bit more expensive while the other one can be found on sale everywhere. I've googled and can't seem to find an answer.

Shimano 105 PD-5700
Shimano 105 SPD-SL

I'm relatively new to cycling and this would be my 1st set of clipless pedals.