Event

Events are occurrences or actions that a program can respond to. They can be triggered by user actions, system notifications, or program state changes. Frontend (Browser) I/O Event Examples:

• User interactions: clicks, key presses, form submissions
• DOM changes: element loaded, attribute modified
• Network: AJAX request completed
• Timers: setTimeout, setInterval completions

Backend I/O Event Examples:

• File system: file read/write completed
• Network: incoming HTTP request, database query finished
• Inter-process communication: message received
• Timers: scheduled task ready

Non-blocking model

The non-blocking model allows a program to initiate I/O operations without waiting for them to complete before moving on to the next task.

Key characteristics:

• Asynchronous operations: Tasks that might take time are started and control immediately returns to the program
• Callbacks or Promises: Used to handle the results of asynchronous operations when they complete
• Efficient resource utilization: The program can perform other tasks while waiting for I/O operations

So what is an event loop

The event loop is a programming construct that waits for and dispatches events in a program. How it works under the hood:

1. Initialization