What is Serverless in Azure and AWS used for? [closed]

Good day,

i have a very basic question about serverless under Azure and AWS.

What is a concrete use case for it? As i understand Serverless is used so that you dont need to care about any of the underlying infrastrucure but rather only use functions for this (Function as a service). A bit confusing for me is that once you created your serverless envirement what can you do? me specifically i look to host a "visual website" where users can request and browse through this website. But after doing the quickstart of Azure for example i only get more confused about it?

Question:

Can somebody explain Serverless and maybe use a concrete use case or if you have experience in it to share it with me?

Thanks in advance