The Difference Between Asynchronous and Synchronous Code

Node.js, being known for its speed, offers asynchronous APIs for operations like network access or filesystem, making it more efficient compared to languages like PHP or Rails. But what exactly does it mean to have an asynchronous API?

An operation is considered asynchronous when it is expected to take a considerable amount of time to complete. By running it asynchronously, other code can continue executing in the meantime, and a designated hook is called when the operation finally ends.

In languages that originally lacked built-in support for asynchronous programming, such as PHP or Python, developers often rely on third-party libraries to implement asynchronous code. If the code is synchronous, the thread blocks until the synchronous operation, like reading from the network or writing a file, is finished.

However, by running code asynchronously, the CPU remains active and can perform other tasks in the queue while waiting for the original process to complete. This capability allows Node.js to handle a larger volume of traffic without relying on additional async libraries.

Tags: asynchronous, synchronous, Node.js, async programming, CPU