Serverless in Plain Words for Non-Technicals
Buying vs Renting
The dilema of Renting Vs Buying is found in every aspect of life. Each side has it's own benefits and from one person to the other the choice will differ, the model has extended from homes, cars, phones to even servers or computers that run applications.
To complicate the mix I'll add the option of usage to the mix, so in the residency prespective, you can buy a home or rent it or you can just reserve few nights in an hotel. Which option will you choose if you can afford all?
Probably the answer depends, you won't buy a home in every place you go and you won't buy a home if you know you're staying temporary.
Computer applications are no different. When a developer or a programmer write code for a program it's just some text, like letters written on a paper with a specific meaning. To make this application able to serve users who visits a website or check a mobile app, this written code needs to be converted to a language computer can understand, i.e. Binary 0s & 1s and this code needs to reside some where. And here you need to ask your self where to reside the application.
Where do applications live?
If you are a single developer, a small team or a small company, you probably don't have a lot of users so reserving a small room or even a bed for your application may be a good case and with that the developer doesn't need to maintain anything, just provide the code and all maintainance is done as part of the price.
This price can be per usage, as in how big is the room, or number or requests, as in how many nights or probably a mix of both.
Another use case to choose the hotel over renting or buying is if you know that your application will only run at specific time, and then stop or stay idle. This is similar to a salesman who visits his customer once a month in a different city, he would probably prefer staying this night in a hotel rather than renting or buying a home in that city.
On the otherside if the application runs more than you expect it too, the cost of running it, or staying in a hotel longer, can be and probably will be higher than if you decide to rent, in addition to having some maintenance.
This hotel concept in application residency is called "Serverless", and the term is coming from the no need in mainting or know anything about the server "Computer" that runs the application, it's all part of the bill, so for the developer his application is "Serverless".
Nothing is perfect with less maintenance you have less control and more ease of use. Owning on the other side requires a lot of maintenance, but you probably end up with more private space to use as much as you want.