volatile

Meaning:

In the context of computing and programming, "volatile" is a keyword used to declare a variable whose value may change at any time, without any action being taken by the code the programmer finds nearby. This is typically used when a variable can be modified by external factors, such as hardware or other threads, outside the direct control of the current code. In essence, marking a variable as volatile informs the compiler that the variable's value can change unexpectedly, and therefore, the compiler should avoid applying certain optimizations that assume the variable remains constant. This ensures that the program behaves as expected in scenarios where the variable's value is subject to frequent and unpredictable updates, enhancing the reliability and correctness of the code.