The Holistic Care

Does a reiki practitioner comes to know evrything jst by talking to another person,or just by his name? How come its possible?

I'm not exactly sure what you mean. If you mean how to do treatments, exercises, hand positions, etc. Then no, we get them from the manuals. Though there is a lot to learn from other practitioners and masters. You can download manuals for free from The Holistic Care here.