Hello Jochen,

https://en.wikipedia.org/wiki/Candlestick_chart

Friendly advice:  Go study and learn for yourself and then come to the forums when you're stuck on something hard that you can't figure out.  I mean this in the nicest possible way when I recommend that you do not skip the step of trying to learn for yourself before coming to the forums and asking.  ;-)

All the basics are available out there for you to learn on your own.  Wikipedia - and the help pages of the various sites.  Also use the SEARCH feature on this forum - 99.9% of all questions have already been answered.

After that:  We guys on the forum love a good puzzle - go work hard to learn everything you can and then come here with your tough questions so we can help out.

Happy bitcoining!