What behavior is ensured by using the volatile keyword in a programming language?

The volatile keyword in Java is used to indicate that a variable's value may be changed at any moment by different threads. It guarantees that:

• Reading and writing the variable will occur directly from main memory, not from the processor cache.
• Changes made by one thread to the variable are immediately visible to other threads.

This helps avoid caching issues and ensures correct handling of variables in a multithreaded environment without using heavier synchronization mechanisms.

Example:

volatile boolean flag = false;

// One thread changes flag
flag = true;

// Another thread sees the updated value of flag without delays
if (flag) {
    // perform actions
}