This tutorial guides developers on how to integrate video calling features into their applications using vanilla JavaScript and the Agora Web 3.x SDK. The Agora Video SDK abstracts away the details of maintaining a low-latency video server, load balancing, and listening to end-user events. The tutorial covers setting up an application structure with HTML, CSS, and JavaScript files, creating a client object, joining a channel, publishing a video feed into the channel, handling remote users' view appropriately, and testing the project. It also provides resources for further learning about building applications using Agora SDKs.