What is the difference between process.nextTick() and setImmediate() in Node.js?

In Node.js, both process.nextTick() and setImmediate() are used to schedule asynchronous code execution, but there are some key differences between them:

1. Timing: process.nextTick() will execute its callback immediately after the current operation completes and before any I/O events or timers. setImmediate(), on the other hand, will execute its callback after the I/O events.
2. Order of Execution: Callbacks scheduled using process.nextTick() will be executed before any I/O events or timers, while callbacks scheduled using setImmediate() will be executed after any I/O events.
3. Priority: process.nextTick() has higher priority than setImmediate(), meaning that if both are called, process.nextTick() callbacks will be executed before setImmediate() callbacks.

Understanding these differences is important for designing efficient and predictable asynchronous code in Node.js.