How Code Runs
The raw binary instructions (1s and 0s) that a CPU executes directly — the lowest-level language a computer understands.
What is Machine code?
This tool translates human-written Java source code into bytecode that the JVM can understand.
What is Java Compiler?
A programming paradigm that organises code around objects which bundle data and behaviour together.
A programming paradigm that organises code around objects which bundle data and behaviour together.
The design principle of hiding complex implementation details and exposing only what is necessary.
What is Abstraction?
In Java, a sequence of characters stored as text — often surrounded by double quotes in code.
What is String?
Compiled Java code is converted into this intermediate format, which sits between source code and machine code.
What is Bytecode?
A software layer that runs Java bytecode on any operating system, making Java 'write once, run anywhere'.
What is Java Virtual Machine (JVM)?
This OOP principle bundles data and methods inside a class and restricts direct access from outside.
What is Encapsulation?
Temporary storage inside your computer that holds currently running programs and data — volatile and fast.
What is RAM (Random Access Memory)?
A data type that can only hold one of two values: true or false.
What is Boolean?
Files produced after source code is compiled but before final linking — intermediate outputs that contain object code.
What is Object files?
The compiled output of a Java source file — the file extension you see after running javac.
What is Class files (.class)?
When a child class acquires the properties and methods of a parent class, avoiding repeated code.
What is Inheritance?
A named, reusable block of code that performs a specific task and can be called from elsewhere in a program.
What is Function?
A Java data type for decimal (floating-point) numbers with double the precision of a float.
What is Double?
This component of the JVM is responsible for actually running bytecode instructions on the host machine.
What is Execution engine?
Requests made by a program to the operating system to perform privileged tasks like reading files or allocating memory.
What is O.S. Calls?
The ability of one method name to behave differently depending on the object or arguments it receives.
What is Polymorphism?
A control structure that repeatedly executes a block of code as long as a condition remains true.
What is Loop?
In Java, this keyword pair controls visibility — one restricts access to the class itself, the other allows access from anywhere.
What is Private vs. Public?