Introduction
Java is a high-level, object-oriented programming language that is widely used for building applications across a variety of platforms — from desktop to web to mobile and enterprise systems.
What is Java?
Java is simple, high level, platform independent, architecute-neutral, secure, robust, multithreaded, distributed and object oriented programming language.
Key Points:
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Developed by: Sun Microsystems (1995), now owned by Oracle.
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Write Once, Run Anywhere: Java code is compiled into bytecode, which runs on the Java Virtual Machine (JVM) — making it platform-independent.
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Used for: Web applications, Android apps, enterprise software, cloud-based tools, and more.
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Syntax: Similar to C/C++, but simpler and safer (with automatic memory management).
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Popular Frameworks: Spring Boot, Hibernate, JavaFX, etc.
Why Learn Java?
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Widely Used and In-Demand Java is used by millions of developers and powers everything from enterprise applications to Android apps and web services. Top companies like Google, Netflix, and Amazon rely on it.
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Beginner-Friendly, Yet Powerful Java has a clean, readable syntax and a vast ecosystem of tools and libraries. It’s great for beginners but also scales well for advanced projects.
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Write Once, Run Anywhere Java is platform-independent. You write code once and run it on any system with a Java Virtual Machine (JVM).
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Robust and Secure With strong memory management, type safety, and built-in security features, Java is ideal for building reliable and secure applications.
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Career and Job Opportunities Java developers are always in demand — especially in backend development, enterprise systems, and Android app development.
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Strong Foundation for Other Tech Learning Java helps you understand key concepts like OOP (Object-Oriented Programming), multithreading, and data structures — which are useful in many other languages too.
Java Versions
| Version | Release Date | Key Features / Notes |
|---|---|---|
| JDK 1.0 | January 1996 | Initial release — basic core API and JVM |
| JDK 1.1 | February 1997 | Inner classes, JDBC, RMI, JavaBeans |
| J2SE 1.2 | December 1998 | Collections framework, Swing, JIT compiler |
| J2SE 1.3 | May 2000 | HotSpot JVM, RMI over IIOP |
| J2SE 1.4 | February 2002 | assert keyword, NIO, logging API, XML parsing |
| Java SE 5 | September 2004 | Generics, enhanced for-loop, annotations, enums, autoboxing |
| Java SE 6 | December 2006 | Scripting engine (JS), improvements in Web Services, JVM monitoring |
| Java SE 7 | July 2011 | try-with-resources, NIO.2, Diamond operator |
| Java SE 8 | March 2014 | Lambda expressions, Streams API, Optional, Date/Time API |
| Java SE 9 | September 2017 | JPMS (modules), JShell, improved JDK structure |
| Java SE 10 | March 2018 | var for local variable type inference |
| Java SE 11 | September 2018 | LTS version, removed JavaFX, HTTP Client API |
| Java SE 12 | March 2019 | Switch expressions (preview) |
| Java SE 13 | September 2019 | Text blocks (preview), dynamic CDS |
| Java SE 14 | March 2020 | Records (preview), instanceof pattern matching (preview) |
| Java SE 15 | September 2020 | Sealed classes (preview), hidden classes |
| Java SE 16 | March 2021 | Records and pattern matching (finalized), new memory APIs |
| Java SE 17 | September 2021 | LTS version, sealed classes, pattern matching |
| Java SE 18 | March 2022 | Simple web server, UTF-8 by default |
| Java SE 19 | September 2022 | Virtual threads (preview), structured concurrency (preview) |
| Java SE 20 | March 2023 | Continued virtual threads and pattern matching enhancements |
| Java SE 21 | September 2023 | LTS version, virtual threads, string templates, sequenced collections |
| Java SE 22 | March 2024 | Unnamed classes, class-file API improvements (preview) |