The exec() function in Node.js creates a new shell process and executes a command in that shell
The key difference between the execFile() and exec() functions is that the first argument of execFile() is now a path to an executable file instead of a command.
The spawn() function runs a command in a process. This function returns data via the stream API. Therefore, to get the output of the child process, we need to listen for stream events.
spawn() does not create a new shell before running a process.
It’s often a good idea to choose spawn() over exec() or execFile() when the command you want to run can output a large amount of data. With a buffer, as used by exec() and execFile(), all the processed data is stored in the computer’s memory. For large amounts of data, this can degrade system performance. With a stream, the data is processed and transferred in small chunks. Therefore, you can process a large amount of data without using too much memory at any one time.
Node.js provides the fork() function, a variation of spawn(), to create a child process that’s also a Node.js process.
The main benefit of using fork() to create a Node.js process over spawn() or exec() is that fork() enables communication between the parent and the child process.