Literary critics tend to fall into groups, characterized by what they think their jobs are. The best criticism is that which seeks to understand and explain a work by analyzing it in its cultural context.
But many critics are not happy doing that. So they do other things, such as evaluating literature based on how well it lives up to some moral or political standard. These efforts usually aren’t helpful at all – unless you are a zealot – but they are common. Other critics,wishing to show how smart they are, take a “formalist” approach, analyzing works according to their “linguistic texture.” Then there are critics who analyze works psychologically. This can be fun if you like it, but… well. There are also critics who like to find comparisons between a work and the author’s life. Most of them work for arcane literary journals. And then there are those who think their duty is to explain nothing more than their own personal impressions.
Interesting Fact: The word “criticism” is from the Greek kritikos, meaning “judge.”