Maybe you’re wondering what a “web operating system" is? In order to explain that, we must take a look at a traditional operating system’s primary functions. The main task of an operating system is to provide a uniform way to access the underlying hardware, with the goal of simplifying the creation of applications. Hence, the "kernel" in an operating system, becomes an API which the developer can consume, to transparently access the underlying hardware of the machine. This is often referred to as "HAL," implying "Hardware Abstraction Layer."
An operating system also contains other functions – but the primary goal is to simplify the creation of apps for the end application developer, by abstracting away the "boring stuff," and making everything easier to use from an application development point of view.