Load balancing in Node.js is a method that allows for distributing incoming application traffic across multiple backend servers. It is important in high-traffic applications to reduce the load on specific servers or instances to ensure that the application remains stable and consistent.

There are several ways to implement load balancing in Node.js, including the use of reverse proxies, cluster module, and third-party packages like PM2 or Nginx. Each method has its pros and cons, and the decision depends on the specific needs of the application.

Reverse proxies work by handling and distributing incoming requests across multiple backend servers, acting as an intermediary between the client and the server. The Nginx web server is a popular reverse proxy option for Node.js applications.

The cluster module in Node.js enables running multiple instances of the application on different processors or servers, with each instance handling a part of the overall workload. This approach is best suited for multi-core machines where each worker thread can handle a specific set of tasks.

Third-party packages like PM2 can help manage the application instances, monitor their performance, and restart them in case of failure. These packages provide a more extensive set of features that make the management of the application's resources and performance more comfortable.

In conclusion, Load balancing in Node.js is a crucial process that enhances the scalability and reliability of applications. It enables the distribution of incoming application traffic to different server instances, minimizing the likelihood of an application crashing due to traffic overloading a specific instance.