A runtime error in Java occurs during the execution phase of a program when syntactically correct code encounters issues like division by zero, out-of-range array access, or invalid argument passing, which are not detected at compile-time but by the Java Virtual Machine (JVM). Unlike compile-time errors identified by the Java compiler due to syntax problems, runtime errors are exceptions that can cause a program to terminate abnormally unless handled using try-catch blocks, allowing the program to continue running. Logical errors, however, result from bugs that produce incorrect output without terminating the program, making them harder to debug than runtime errors. Common causes of runtime errors in Java include trying to divide by zero, accessing non-existent array elements, and insufficient memory, which are often addressed by using error monitoring tools like Rollbar that automate tracking and managing errors to facilitate smoother production code deployment.