A lab report is basically an analysis of a scientific process.
Hence, everything done during an experiment is discussed in your lab report. Lab reports are important when it comes to lab courses and they also contribute significantly to your final grades.
Sometimes you teachers help you by giving an outline for your lab report. When you enter high school, you have to do everything on your own.
A book report is a formal and informative piece of writing where unlike a book review you aren’t required to give your personal opinions and perform a deep analysis.
A book report is much simpler than writing a book review; here you discuss the contents of the book provide background information about the author and his/her background to help the reader understand the author’s point of view.
Along with that, a book report summarizes important aspects such as the story, plot, setting and characters.
Remember, that the reason your professor has assigned a book report is to check your level of understanding of the book.