What do you understand by the term rhetorical contexts/strategies? How is an understanding of this important in academic reading and writing?

Context is the environment or situation for which the work is written. If you are the author, you must understand your reading audience to communicate effectively. For example you would use much different language in reporting the findings of original research in a peer reviewed journal than you would in a general interest newspaper or website. If you are the reader, context is important as well. You need to understand who the author is and their intent with writing the work to fully understand its message.