TIL: Today I Learned Sinatra

So, I've been slowly but steadily making progress in learning the Ruby programming language. As a beginner, I've heard the terms "front-end development", "back-end development", and "full stack development" but what exactly do they mean? Well, I learned that Ruby is a backend language. The backend is comparable to the gears in a clock; they are essential for a clock or watch to work but the owner doesn't actually see the gears turning (depending on some watches and clocks). The only difference is, users almost never will see or access server-side data infrastructure. Why you may ask? My answer is drum-roll please backend frameworks; such as Ruby on Rails and Sinatra. Sinatra is a lightweight framework that enables developers to make small applications
I understand that users don't actually see routes, HTTP calls or api tokens and most users are not aware that they can change the route of an address to get to the desired content (granted the content exists and unless that user is a computer whiz or works in the tech industry).