.const applies to bindings ("variables"). It creates an immutable binding, i.e. you cannot assign a new value to the binding. const person = { name: "Leonardo" }; let animal = { species: "snake" }; person = animal; // ERROR "person" is read-only Object.freeze works on values, and more specifically, object values. It makes an object immutable, i.e. you cannot change its properties. let person = { name: "Leonardo" }; let animal = { species: "snake" }; Object.freeze(person); person.name = "Lima"; //TypeError: Cannot assign to read only property 'name' of object console.log(person);