Java is known for its object-oriented, platform-independent, simple, secure, and multi-threaded features. It’s designed to have minimal implementation dependencies, making it a widely used language for developing portable applications.

The Java Virtual Machine (JVM) is an engine that provides a runtime environment to execute Java bytecode. It converts Java bytecode into machine language, executing it line by line. JVM is platform-dependent, thus ensuring Java's platform independence at the execution level.

JDK (Java Development Kit) is a full-featured software development kit for Java, including JRE and development tools. JRE (Java Runtime Environment) provides libraries, Java Virtual Machine (JVM), and other components to run applications written in Java. JVM is part of JRE and facilitates the execution of Java bytecode.

The ‘final’ keyword in Java can be used with variables, methods, and classes. When a variable is declared as final, its value cannot be changed. When a method is final, it cannot be overridden by subclasses. A final class cannot be subclassed, ensuring that the class remains unchanged throughout the program.

Java’s garbage collection mechanism automatically manages memory by reclaiming the space occupied by objects that are no longer in use. The JVM's garbage collector identifies these objects and removes them to free up memory, thus preventing memory leaks and enhancing performance.

In Java, ‘==’ is a reference comparison operator that checks if two references point to the same object in memory, while the ‘equals()’ method is used to compare the values within the objects for logical equality. It's important to override the ‘equals()’ method to enable proper value comparison.