Lambda Expressions Anonymous functions that provide a clear and concise way to implement single-method interfaces using an expression. --- 🔹 2. Functional Interfaces Interfaces with a single abstract method, used as the target types for lambda expressions and method references. --- 🔹 3. Streams API A powerful abstraction for processing sequences of elements (collections) in a functional and declarative manner. --- 🔹 4. Default Methods Allow interfaces to have method implementations so existing interfaces can be enhanced without breaking backward compatibility. --- 🔹 5. Static Methods in Interfaces Interfaces can contain static methods with implementations, which can be called independently of any object. --- 🔹 6. Method References A shorthand notation to call methods or constructors using the :: operator, making code more readable. --- 🔹 7. Optional Class A container object used to represent the presence or absence of a value, helping to avoid NullPointerException.