What are the characteristics of comedy of manners?
A quick answer to your question is that a comedy of manners is a work in which the author is using humor and/or satire to point about the flaws and weaknesses in people's behavior. It frequently focuses on a specific class of characters. One of the best examples of this type of work is Pride and Prejudice.
There is a more detailed commentary on the enotes page I have listed in the references below.