Overview of Serverless Applications

As we create this overview of serverless applications, we ask, what is serverless? And what are serverless applications (apps)? These questions are a great way to kick off the Complete Developer’s Guide to Serverless Apps.

The term “serverless” has been used for several years. And like the word “cloud,” it is not always clear from the context exactly what the term means. The goal of this section is not only to give a clear explanation but to equip you to determine which meaning of “serverless” is most appropriate in a given circumstance.

In the guide, we use a more specific term, serverless apps, to refer to a way of developing and running code. After defining the more general term “serverless,” we’ll give a concise definition of “serverless app” that is used throughout the remainder of the guide. Along the way, we’ll also explain “serverless functions,” “Functions-as-a-Service (FaaS),” and “cloud functions” — all terms that are relevant in this guide. If that sounds like a lot, don’t worry. We’ll see that the only terms we really need to keep in mind are serverless apps and functions.

At the end of this chapter, we’ll also take a moment to define WebAssembly (Wasm), a popular technology that powers some serverless app platforms, such as Fermyon Cloud and Spin.