Deontology: In one sense, a deontology is simply theory of our duties, ... a deontological theory denies in some way that the good or what is of value, always takes priority over the right or duty.
A deontological ethical system focuses on duty over that which is good or has value. For example, it may be good to show mercy, but it is duty to deliver justice.
Teleological ethics is the opposite of this and asserts that duty does not exist except as the consequence, the end result of what is morally good and right.
Teleology: It means the doctrine that there is design, purpose, or finality in the world, that effects are in some manner intentional, and that no complete account of the universe is possible without reference to final causes.