That's all it means. Your body learns how to do a movement making it easier to do that movement again. This isn't something that just fades away the same way you will always know how to ride a bike. Will you ride a bike better if trained on one daily? Yes. But you won't forget how to ride. I am still trying to figure out why people are separating strength gains from mass gains. Who is doing this and why? You have to get stronger to get bigger. I think some of you need to spend less time trying to read the latest strength coach's training notes and more time learning the basics well.
If you have to ask about "synaptic facilitation" and truly don't understand that this simply means how your mind adjusts to doing an exercise or any movement at all, then you probably shouldn't be trying someone's program based on the concept before you even get basic understanding of the concept down.
Baby's learn how to do a movement. This movement then get hardwired into normal brain function and activity. If that person grows up and gets into a car accident and damages the part of the brain that controls that action, they can often reroute the nerve impulses in order for a new section of the brain to learn the response.