What is the Difference Between System Call and Interrupt?

The main difference between a system call and an interrupt lies in their purpose and how they are triggered. Here are the key differences between the two:

• System Call:
• A system call is a method that enables a user process to interact with the kernel of the operating system.
• It allows a program to request services from the kernel, such as reading information from files, managing memory, or controlling data flow between computers.
• System calls are synchronous, meaning they occur at a fixed time, usually determined by the programmer.
• They are triggered by executing code, and the process continues to execute its code stream.
• Interrupt:
• An interrupt is a notification from an external hardware component or software to the CPU/Microprocessor about an event that needs handling in software, usually by a driver.
• Interrupts are asynchronous, meaning they can occur at any time and are not determined by the programmer.
• They are triggered by events such as the completion of an instruction, hardware or software signaling for an event, or timers reaching their final countdown value.
• Interrupts do not require the kernel's attention, and the process does not continue to execute its code stream when an interrupt occurs.

In summary, system calls are used for user processes to communicate with the OS kernel and request services, while interrupts are notifications from external hardware or software to the CPU about events that need handling. System calls are synchronous, while interrupts are asynchronous.

Comparative Table: System Call vs Interrupt

Based on the search results, here is a table comparing system calls and interrupts:

In summary, system calls are software-initiated requests for services from the kernel, enabling user processes to interact with the operating system. In contrast, interrupts are hardware-initiated events that require immediate attention and provide a way for hardware devices to communicate with the operating system.