What is Java?
- Java course
- Beginner
- Lesson 1/116
- 4 min
Learn that Java is a compiled, object-oriented and platform-independent language.
What is Java?
Java is an object-oriented, platform-independent programming language created by Sun Microsystems in 1995. Today it is developed by Oracle and Java 21 LTS is the latest long-term support release.
Java is a compiled language: with javac you turn your source code into a .class file (bytecode). This bytecode runs on any JVM (Java Virtual Machine). Because of this, Java code runs the same way on Windows, Linux and macOS.
Java is widely used for Android apps, web servers, big data systems and enterprise software.
What can you build with Java?
Java has a wide range of use cases:
- Android: a large share of mobile apps are written in Java
- Web servers: large systems with Spring and Jakarta EE
- Big data: tools like Hadoop and Spark are Java-based
- Enterprise software: banking and insurance systems
This versatility makes Java one of the most popular languages in the world.
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What runs a Java program?
- A web browser
- Only a compiler
- The JVM (Java Virtual Machine) Correct answer
- The OS kernel
Explanation: Java bytecode runs on the JVM.
2 Match the concepts
| Term | Meaning |
|---|---|
Java |
Programming language |
JVM |
Runtime |
JDK |
Development kit |
javac |
Compiler |
3 Which can NOT be done with Java?
- Build an Android app
- Write a web server
- Build a big data tool
- Write an OS kernel Correct answer
Explanation: Kernels are typically written in C; Java is not suited for that.
4 Java is an ___ language
Java is an ____ language.Java is an object-oriented language.Explanation: Java is an object-oriented language.