The concept of encapsulation in OOP allows us to define all of the necessary members for an object to function while hiding the internal implementation details from the application using the object. This is a very powerful concept for us to use because it allows us to change the internal workings of a class without breaking any of its dependent objects. This could come in the form of either private members or private method implementations. The contract that has been established remains the same and the functionality that it provides is consistent, however, improvements are able to be made. In the following code segment, you can see how hiding certain members from the calling application will be beneficial:

interface IActivator {
    activateLicense(): boolean;
}
class LocalActivator implements IActivator {
    private _remainingLicenses: number = 5;
    constructor() {
    }
    public activateLicense(): boolean {
        this._remainingLicenses--;
        if (this._remainingLicenses...