1. An admission may, under certain circumstances, bind strangers as well, whereas estoppel binds only parties and privies thereto. It cannot be taken advantage of by strangers.
2. Estoppel being a rule of evidence, an action cannot be founded on it, whereas an action may be founded on an admission. 3. An admission of a party is strong evidence against him, but he is at liberty to prove that such admission was mistaken or untrue. But, if another person has been induced by it to alter his position, the party is estopped from disputing its truth with respect to that person. When an admission has been acted upon by another person, the admission is an estoppel, and the estopped party is required to make good his representation; in other words, the admission is conclusive. An estoppel differs from an admission in that it cannot be taken advantage of by strangers. It binds only the parties and privies.
An estoppel is only a rule of evidence, for an action cannot be founded upon it.