Synchronization issues occur when multiple processes or threads attempt to access shared resources simultaneously, leading to conflicts or inconsistent data. This is common in computer systems where programs need to coordinate their actions to avoid errors, such as when two users edit the same document at the same time. To manage synchronization issues, developers often use techniques like mutexes, semaphores, or locks. These tools help ensure that only one process can access a resource at a time, maintaining data integrity and preventing crashes. Proper synchronization is crucial for the reliability of applications, especially in multi-threaded environments.