wtf is jdk?

This repository is a read-only mirror of the source code for the Java Development Kit, or JDK. The JDK is the underlying engine that makes Java applications run. It includes the tools needed to build Java programs, the runtime environment that executes them, and the core libraries that Java developers rely on every day. This mirror is a copy of the original OpenJDK project, synced so that people who prefer using GitHub can easily browse the code, read its history, and link to specific lines without visiting the original hosting site. At a high level, this repo contains the complete source code for the Java platform itself, everything from the compiler that translates Java code into runnable instructions, to the virtual machine that actually runs those instructions, to the vast standard library of built-in functions. The README itself is minimal: it points you to external documentation for build instructions and links to the OpenJDK community site and bug tracker for everything else. If you want to actually compile the project from source, you would need to follow the linked building guide, which walks through the required tools and steps. This project is primarily for developers who contribute to Java itself, researchers studying how a major programming language is implemented, or engineers who need to patch or customize the JDK for specialized use cases. For example, a company running Java on unusual hardware might need to tweak the runtime, or a security researcher might want to audit the core libraries for vulnerabilities. Most everyday Java developers never need to look at this code, they simply install a pre-built version and start coding. One notable thing is that this is a one-way mirror. You cannot submit pull requests or open issues here. All real development happens on the original OpenJDK infrastructure, and this copy exists purely for convenience and visibility on GitHub.