1What is Java?
Java is a high-level, object-oriented programming language where the whole concept runs on top of a virtual machine called the JVM. Instead of directly compiling to machine code like C/C++, Java compiles to bytecode, and this bytecode runs inside the JVM. Because of this extra layer, the same Java program can run on any OS as long as that OS has a JVM installed. That is what write once, run anywhere means — the code stays same but the JVM implementation changes internally for each OS.
Java handles memory on its own using something called Garbage Collection. This means you don’t manually free memory (like in C). JVM continuously tracks objects in memory; once an object has no references pointing to it, GC clears it out, preventing memory leaks.
Java is widely used in enterprise systems because it focuses on stability, long-term maintainability, and strong type safety. Java gives predictable performance because everything is strict: types, memory allocation, exceptions, multi-threading model etc.