Style Text Input as Form Control Question

Firstly, I am not sure if this is the right place to post these questions so if it isn’t, please let me know.
The question I’m doing is from the Responsive Design with Bootstrap section. Why do we need to change the input class from “text” to “form-control”? I don’t see much of a change besides form control extending the width of the submission box.

Your confusion is understandable, especially as the only changes we see in this section are the little mobile window on the right. I’d be hard pressed to say exactly what the form-control class is doing that text is not, but often times Bootstrap classes will interact with each other in order to create some desired behavior as opposed to a dramatic visual change. In this case, I am sure the for-control class makes the input responsive, and it seems to have styled the submit button as well. This would be a good time to introduce you to the documentation for Bootstrap. Try looking things up as you’re introduced to them. Reading documentation is a necessary skill for developers, and the sooner you get started, the better.