Final answer:
The main difference between a trap and an interrupt is that a trap is a synchronous event caused by the program currently running, while an interrupt is an asynchronous event triggered by external factors.
Step-by-step explanation:
The main difference between a trap (exception) and an interrupt lies in their source and their purpose. A trap, which can also be called an exception, is a type of synchronous interrupt caused by an error or a condition that needs handling by the operating system during the execution of a program. It is 'synchronous' in the sense that it results directly from the execution of a specific instruction.
In contrast, an interrupt is an asynchronous event that occurs independently of the current program execution. It is typically used to handle events like hardware signals or system clock ticks that require immediate attention by the operating system or other control subroutine. The key distinction being that interrupts are generated by external sources or hardware devices, while traps are generated by the execution of the program itself or by the CPU to indicate an error or a system call.