If you are visiting this page through my user-page, then you would have found this topic listed among my interests.
It will be useful for you here to have some preliminary idea of literary criticism. What is literary criticism? The obvious answer: criticism of literary works. Again, even more obviously, that cannot be the simple answer to the question. We could even begin with asking : is there a profession to which a "critic" belongs? Who, in other words, can be a "critic" ? Such questions are not silly or irrelevant. I could even pose the idea -- am I a critic? Many writers (and thinkers) over time have analysed and judged literary writing. Can we call them 'critics' too ? A broad answer to many such questions is, yes, anyone can be a critic; I am also a critic; many writers and thinkers have also been critics. But if we look for a professional category we would not find anyone who is a 'critic' and nothing else ! You would have understood by now that 'criticism' has to do with analysis and a judicious understanding. Critics look for subtle meanings in novels, etc. They can measure the value of a literary work. So, it is indeed ponderous or weighty work because it involves a breadth of knowledge, aesthetic or artistic judgment, and a sensitivity to language.
There have been many great critics. Plato, and Aristotle, for instance, are names you may be familiar with. Plato was not a literary critic, while Aristotle wrote a theoretical piece on drama, and epic, called the Poetics.