in short: It is a technique which is used to create roots on a stem or branch in order to create a new plant and/or a better root-flare. In Dutch it is called macotteren.

Read about it: www.bonsai4me.com/AdvTech/ATLayering.html

ah, yes, i know what it is, i just didn't know the name in english.

thanks jelle for clarifying

For all being dubious about growing from seed.. Have a look here too: www.fukubonsai.com/2b7c.html