Promise
A promise is a commitment by someone to do or not do something. As a noun promise means a declaration assuring that one will or will not do something. As a verb it means to commit oneself by a promise to do or give. It can also mean a capacity for good, similar to a value that is to be realized in the near future.
In the law of contract, an exchange of promises is usually held to be legally enforceable, according to the Latin maxim pacta sunt servanda.
Types
There are many types of promises. There are solemn promises, such as marriage vows or military oaths. There are legal contracts, enforceable by law. Or, there are fairy tale promises, regrettable and problematic at the time they must be honored. And lastly, there are election promises, commitments that most people realize will later be shaped by politics and compromise.
Both an oath and an affirmation can be a promise. One special kind of promise is the vow.
A notable type of promise is an election promise. Election promises are pledges that will be later shaped by politics and the cooperation of individuals.