Cloud basically just means running software on other peoples' computers in a data center somewhere. Serverless is a subset of cloud. It's a way of building and deploying cloud apps.

Serverless implies a very high level of abstraction when interacting with cloud infrastructure. Traditionally app developers have consumed cloud infrastructure on the level of individual boxes running operating systems. Obviously these don't usually correspond to actual physical machines, but the OS box is the unit of abstraction presented to people running building and deploying cloud apps. Serverless apps are typically based on the "function" (one invocation of some small bit of logic) as the unit of consumption for cloud infrastructure - e.g AWS Lambda. They also typically embrace high-level abstractions for managing data - e.g. building against DynamoDB as opposed to your own Cassandra cluster running on EC2.

The term "serverless" is annoying as heck. I mean, sure, you're not fiddling with nginx configs, but you're even more tightly dependent on running in a cloud environment. It really should be "servermore".

It's analogous to "functional" and "object-oriented". They're both popular buzzwords. One has been beaten to death and sometimes implemented poorly enough to gain a bad rap. The other is still new enough to serve as a vessel for software people to pour in all their vague hopes and unrealistic dreams.

At some point, the new hotness will be the old tiredness, and the cycle will repeat.

Serverless apps run in reaction to an event such as a web request or a file upload. In the serverless model your app has functions that run in response to these events. The classic cloud model is you pay for a server or container that is constantly running.

Its kinda equivalent to a timeshare condo vs renting a condo. Your functions only run when they are called.

Here:

>When I say serverless, I’m referring to the function-as-a-service pattern. A serverless system must scale dynamically per request, and not require any capacity planning or provisioning. For instance, you can connect to FaunaDB serverless cloud in moments, and scale seamlessly from idea to runaway hit.