When you instantiate an object that is a member of a subclass, the constructor executes first.

a. Inheritance is a one way street.  A child inherits from the parent only. A parent class does not have access to the child's methods or data.
b. instanceof operator - determines whether an object is a member or descendant of a class.

3. Overriding SuperClass methods. Sometimes the superclass data fields and methods are not entirely appropriate for the subclass objects; When true superclass has to be overriden.
a. Polymorphism - "many forms" using the same method name to indicate different implementations.
b. When you create a method in the child class that has the same name and parameter list as a method in its parent class, you override the method in the parent class. The child�s version is used.
c. If the parent�s method has the same name but a different parameter list, the child overloads the parent class and the child has access to both versions.
d. The key word super can be used to override a parent�s method.  
e. subtype polymorphism is the ability of one method name to work appropriately for different child (sub class) objects of the same parent class. 
f. Any child class object has all the attributes of its parent, but all of those attributes might not be directly accessible.
g. When a child class method overrides a parent class method, and you use the method name with a child class object, the child class method version executes.

4. Calling constructors during inheritance. When you instantiate an object that is a member of a subclass two constructors are called: the base class and the derived class. The superclass constructors must execute first and then the subclass constructor executes.
a. Every Java object automatically is a child of a class named Object. When you instantiate any object, you call its constructor and the Objects constructor and when you create parent and child classes of your own, the child classes use three constructors.  
b. When you use a class as a superclass and the class has only constructors that require arguments, you must be certain that any subclasses provide the superclass constructor with the arguments it needs.

5. Accessing Superclass constructors. When a superclass has a default constructor, you can create a subclass with or without its own constructor. If the subclass contains no constructor, all subclass objects use the superclass default constructor when they are instantiated.
Format that calls a superclass constructor:

a. The

You cannot access a private data member of an object with

instead you use

Information Hiding with private data can be altered by the methods you choose and only in ways that you can control. Private members of the parent class are not accessible within a child�s class methods.
a. Using the keyword protected provides you with an intermediate level of security between public and private access. Protected members are those that can be used by a class and its descendants. When a child class is allowed direct access to a parent�s fields, the likely hood of future errors increases.

7. Methods you cannot override in a subclass are:
a. Static methods - a subclass cannot override declared static method in the superclass.
b. A subclass cannot override final methods in it superclass.
c. In Java, instance method calls are virtual method calls - the method used is determined when the program runs.
d. A subclass cannot override methods that are declared static in the superclass.
e. A subclass cannot override methods that are declared final in the superclass.
f. A subclass can override private methods as well as public or protected ones.