What is the role of the ClassLoader mechanism in the class loading process in the JVM?

The ClassLoader mechanism in JVM is responsible for dynamically loading classes into memory during program execution. It allows the JVM to load class bytecode from various sources (file system, network, archives, etc.) as needed, rather than loading all classes at startup.

Main roles of ClassLoader:

• Searching and loading class bytecode.
• Checking and verifying the loaded class.
• Isolating namespace for classes, enabling different versions of the same class to be loaded in one JVM.
• Supporting a hierarchy of loaders (Bootstrap, Extension, System/Application), where each loader can delegate loading to its parent.

Example: when a class is used for the first time in code, the JVM searches for the corresponding .class file via ClassLoader, loads it into memory, and links it with the current execution process.