What is the role of the Java runtime environment and what does it handle in the process of running applications?

The Java Runtime Environment (JRE) is responsible for executing Java bytecode of applications. Its main functions include:

• Class loading — loading and initializing classes and interfaces.
• Interpretation or compilation of bytecode — executing code using an interpreter or JIT compiler.
• Memory management — allocating memory for objects, managing the heap, garbage collection.
• Security — verifying bytecode, access control.
• Exception handling — managing errors during execution.

In Android, the runtime environment is represented by Dalvik or ART, which perform similar functions adapted for mobile devices.

Thus, the runtime environment provides isolation, portability, and resource management for Java applications.