"To be, or not to be" is arguably William Shakespeare's most famous line. Found in Hamlet (3.1.56), Hamlet is considering life. He finds that life may not be worth living if it continues to be so challenging. Hamlet is questioning whether he should move forward with his plan to murder Claudius (the one responsible for his father's death) or end his own life.
"To be" refers to the verb "being" in regards to existence. Hamlet is essentially questioning if he should continue his own insufferable existence or end his pain. Unfortunately, Hamlet also questions what the afterlife holds. His fears of the unknown force him to consider which is the "lesser of two evils" (when given two bad choices, one tends to be "less bad" than the other), ending the life of Claudius or his own.
The 2B speech addresses two concepts. First, whether life is worth having and second the impediments of turning resolve (resolution) into action. The second concept naturally flows from the first because Hamlet realizes that though we just "can be" without doing anything, we can't simply "not be". Hamlet's exploration of "not being" involves 2 ways to "not be". The first is taking arms against a sea of troubles. The second is making your own quietus with a bare bodkin. Either way "not being" requires some forward action beyond the mere resolution to do so. This is the second part of his soliloquy: turning resolution into any action is generalized from the specific example of doing something to "not be".
In light of life's burdens is life worth having or not. As nobility Hamlet has had his preconceived notions of what it is to be noble. The chink in the armor is his realization that nobility is not a state of mind bestowed at birth rather it must be acquired. The ultimate conclusion he draws by the end of the soliloquy is that if one settles on being noble of mind and nothing more then he is a coward -- a paradox, hardly keeping with nobility. We see this expanded in Hamlet's last soliloquy in 4.4. "How all occasions do inform against me..." where Hamlet watches Prince Fortinbras resolve to act for an "eggshell". Again the dichotomy of passive forbearance versus the nobility of action.