Is there a PDF file or a book that explains the capabilities of the nodes of this software?
Maybe this resource https://docs.knime.com/ helps you to some more information you are looking for.
@alex1368 you can start with the software documentation
And continue with the cheat sheets that would give you a quick overview.
Then if you like reading there are the book from KNIME press
On the KNIME hub there will be a description for every node used
Other learning resources are being outlined in this recent article
Or you can also just go through the nodes and try them. The nodes are categorized. Each node also has its description embeded.
The more you use the nodes, the more you will get familiar with them. I’ve never actually read any of the documentation - did not even know about https://docs.knime.com