How do you practice the 10 frame buffer?

[SmAshiok]

First off, is my friend just BSing me when he says that there's a 10 frame input buffer in this game? He and I were playing and I was getting frustrated with my inputs not happening when I input them, and he suggested that I wasn't following the 10 frame buffer rule. I had no idea it was even a thing, as Smash 4 has been my only real fighting game. He said if I had played other fighting games, I would know what it is, but I don't.

Can someone shed some light on it? I've honestly never heard of it, and am still skeptical of its existence.

 

[PLATINUM7]

Read this. http://www.ssbwiki.com/Buffering
Essentially you can input actions up to 10 frames before they can executed. The input will be carried out the first frame possible.