A constructor is a special function in programming that is used to create and initialize objects. When you create a new object from a class, the constructor automatically runs to set up the initial state of that object. For example, if you have a class called Car, the constructor can set properties like color and model when you create a new Car object. In many programming languages, constructors can take parameters, allowing you to customize the object's properties at the time of creation. This makes it easier to manage and organize your code. For instance, you might have a constructor for Person that takes a name and age to create a new Person object with those specific details.