How do you understand the differences between written history source, historical research and historical novel?

The source is the source, this is the beginning of the research. Research is what builds on the source for this:
Written historical sources – books or old documents describing events.
Historical research – analysis and synthesis are used.
A historical novel is a novel that unfolds against the backdrop of historical events.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.