What is the difference between API and system call?

The main difference between API and system call is that API is a set of protocols, routines, and functions that allow data exchange between various applications and devices whereas a system call is a method that allows a program to request services from the nucleus..

An API consists of protocols and functions that define communication methods between various components. It can be a web-based system, an operating system, a database, or a software library. On the other hand, a system call is a method that allows a program to request services from the kernel of the operating system.

Key Areas Covered

1. What is API
     – Definition, Functionality
2. What is system call?
     – Definition, Functionality
3. What is the difference between API and system call
     – Key differences comparison

Key terms

API, Kernel, System Call

What is an API

Different devices and apps share data with each other. Some of them include online reservations and booking systems. API ( Application Programming Interface ) Helps establish connectivity between devices and applications. Furthermore, it is an interface that takes requests from the user and informs the system about what needs to be done and returns the response to the user.

For example, suppose an online travel service aggregates information from multiple airlines. The travel service interacts with the airline’s API. The API takes requests to reserve seats and select meals from the travel service to the airline system. It then sends the responses from the airlines to the online travel service, and the travel service displays the details to users. This is a real world application for an API.

What is a system call?

A computer works in two modes: user mode and kernel mode. The execution of a program is in user mode. When the program requires RAM or a hardware resource, it sends a request to the kernel and the mode changes from user mode to kernel mode. System calls refer to these requests. After completing the task, the mode changes back to user mode. Also, the mode changes continuously. This transition is also called context switch.

There are several types of system calls. Some of them are the following.

Call process control system. – Create, run, terminate processes, set process attributes, etc.

Call file management system. – Create, read, write, delete files, open and close files, set file attributes, etc.

Call device management system. – Request and release devices, set device attributes, etc.

Call information management system. – Get and set system data, get and set date and time, etc.

Call communication system. – Send and receive messages, transfer status information, create and delete communication connections, etc.

Difference Between API and System Call

Definition

An API is a set of protocols, routines, and functions that programmers use to develop software to facilitate interaction between different systems. In contrast, a system call is a programmatic way in which a computer program requests a service from the kernel of the operating system it is running on. Therefore, these definitions contain the main difference between API and system call.

Use

Another difference between API and system call is their usage. An API helps to exchange data between various systems, devices, and applications, while a system call allows a program to access services from the core of the operating system. 

conclusion

The main difference between API and system call is that API is a set of protocols, routines, functions that allow data to be exchanged between various applications and devices, while a system call is a method that allows a program to request services. from the core.

Reference:

1. What is an API?, MuleSoft Videos, June 19, 2015, Available here.
2. “Application programming interface”. Wikipedia, Wikimedia Foundation, November 16, 2018, Available here.
3. Explanation: System Calls and Types of System Calls in the Operating System, Last Moment Learning, Jul 12, 2017, Available here.

Courtesy image:

1. “Open-APIs-v5” By Camwilliams96 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “System Call Interface” By System Call Interface – (CC BY-SA 4.0) a via Commons Wikimedia