This article offers some guidelines for blocking in boxing. For rookies and seasoned boxers, blocking is probably the easiest active defense there is. Along with being relatively easy, it is probably the most effective active defense there is. What more could you ask for?
Slipping punches is the most basic form of dodging, at least in boxing. It is not easy to get wrong, but some would-be boxers manage to mess it up. However, when it is done successfully, for a brief moment it makes you look untouchable.
If you ask anyone what boxing looks like, most people would imagine a boxer bobbing and weaving.