Final answer:
A critical section is a part of a process that accesses shared resources and must be synchronized to prevent concurrent access. It is essential for maintaining data integrity in concurrent programming.
Step-by-step explanation:
Critical section is a section of code within a process that requires access to shared resources and that must not be executed while another process is in a corresponding section of code. This concept is central to concurrent programming and multithreading, where multiple processes or threads run in parallel and need to interact with shared data or resources without causing inconsistency or corruption.
To manage such interactions, synchronization mechanisms like mutexes (mutual exclusion objects), semaphores, or monitors are used. These mechanisms ensure that only one process or thread can enter its critical section at a time, thereby preventing race conditions. An example would be when two threads try to increment the same counter variable; without proper synchronization, they could interfere with each other and lead to incorrect results. When a thread enters the critical section, it acquires the lock, ensuring that no other thread can enter it until the lock is released.