Java Fundamentals refer to the core concepts and principles that form the foundation of the Java programming language. These include understanding its syntax, data types, operators, control structures (such as loops and conditionals), and object-oriented programming principles like classes, objects, inheritance, and polymorphism. Java also emphasizes key features such as exception handling, interfaces, and the Java Development Kit (JDK), which provides the necessary tools for writing and compiling Java applications. Mastery of Java fundamentals is essential for building efficient and scalable applications, as well as for understanding more advanced topics in software development using Java.