Java is a high-level, object-oriented programming language that was developed by Sun Microsystems (now owned by Oracle Corporation) in the mid-1990s. It is known for its platform independence, which means that Java programs can run on various hardware and operating systems without modification, thanks to the Java Virtual Machine (JVM).

Key features and concepts of Java include:

1. **Platform Independence**: Java code is compiled into an intermediate form called bytecode, which can be executed on any platform that has a compatible JVM. This "write once, run anywhere" capability is one of Java's most significant advantages.

2. **Object-Oriented**: Java is a fully object-oriented programming language, which means that it emphasizes the use of objects and classes to model and organize code.

3. **Robust and Secure**: Java includes features like automatic memory management (garbage collection) to help prevent common programming errors such as memory leaks. It also has built-in security features to protect against various security threats.

4. **Multithreading**: Java supports multithreading, allowing developers to create concurrent and parallel applications easily. This is essential for building efficient and responsive software, particularly in the context of modern, multi-core processors.

5. **Rich Standard Library**: Java provides a vast standard library (Java Standard Library) that includes classes and methods for performing a wide range of tasks, from basic I/O operations to advanced data manipulation and network communication.

6. **Community and Ecosystem**: Java has a large and active developer community, which has contributed to a rich ecosystem of libraries, frameworks, and tools. This ecosystem includes popular frameworks like Spring, Hibernate, and JavaFX.

7. **Portability**: Java applications can be distributed as JAR (Java Archive) files, making it easy to share and deploy software across different environments.

8. **Enterprise-Ready**: Java is widely used in enterprise software development. It has features like scalability, reliability, and support for distributed computing, making it suitable for building large-scale and mission-critical applications.

9. **Open Source**: While the core Java language is managed by Oracle, many Java technologies and libraries are open source, fostering collaboration and innovation in the Java community.

Java is commonly used in a variety of application domains, including web development, mobile app development (Android applications are primarily written in Java), desktop applications, and server-side development. It has remained a popular and influential programming language for decades and continues to evolve with new features and updates.