RC Model Helo

I did 42+ years in Air Ministry/RAF/MoD as a military meteorologist (including a tour on a helo Station). So I know the physics of Helo operations.
My grandson got a tiny RC helo for Xmas. It does not have a tail rotor. It has 3 vertical co-axial(?) rotor discs. It does all the good things (hover, up, down, left, right, back, forward, etc). How does it do this without a tail rotor? Too difficult!
Please tell me how it does this (or where I can go to find out) – and why do real helos not use the same system?
Rgds
Resmoroh