A genre is a category of creative works that share characteristics or key elements in subject matter or style, and which represent a shared expectation between the author and the reader. For example, in the superhero movie genre, we expect to see characters in the roles of hero and villain, with elements of fantasy (i.e. superpowers) and action in the plot. Recognizing familiar elements of the genre can help us to follow the plot and relate to the characters.
Academic writing is also a genre, with predictable features and styles that vary only slightly across the different disciplines. Knowing these elements and the familiar "plot" of a scholarly article or book can help you to read and understand academic texts efficiently and effectively.
If academic writing was a superhero movie: