Over the last few years as technology has improved and the cloud providers built out more and more infrastructure, serverless began to grow.
Serverless doesn't mean there is no server. What serverless means is that you don't have to worry about the server. The provider does.
This allows us to focus on our functions and code. What our functions do without worrying about managing updates to our server or running virtual machines. We don't even have to worry about scaling up or down.
I've already been using Azure functions alot and I've a bunch of blog posts on Azure Functions already: Azure Functions
But as it stands I'll find it hard to switch I like Azure functions. They are quick and easy to setup and run.
Google has a few options for serverless. Google Functions is built into the Google cloud.
Firebase is another option from Google for serverless
AWS lambda is the offering from AWS for serverless. It is a bit more tricky then the others to setup and get running.
Cloudflare have started into the serverless world with Cloudflare workers. Cloudflare workers give developers a place to deploy our code closer to the customers.