Simple. No frills, no Velcro, no extra padding, while still offering protection and feel. I've been a fan of lightweight, thin gloves without a lot of fluff for a long time. These are the real deal, and they get the job done. Mind you, these are not work gloves. They are lightweight because I require a glove where I can feel bars and the controls extremely well. Yes, they will protect you from cuts, scrapes, branches, rocks, but they are not the heavy duty mechanic style gloves some people like to run while riding. Give them a test drive and see if you like them as much as me. Best for the warmer riding days. If it's really cold out, these might not be the gloves for that riding day.
I have average sized hands and wear a size Large in all my other riding gloves. I wear size large with these gloves too. Hopefully that helps you know which of the three sizes to order.