What are the uses of HTML frameworks? Isn't it possible? Example bootstrap_html/css_WEB-ITnose

I downloaded the HTML framework bootstrap and found the drop-down menus inside. Even without this framework, I can still write! Is there any special use of bootstrap? I just learned it today and don’t quite understand the concept of framework.

Reply to discussion (solution)

Although these things can also be written, it is not better to use ready-made ones, even if some special things need to be done The effect is only to change a small part of it, and the workload is very small. Remember: all frameworks are used to reduce workload and improve work efficiency. It will take you a week to adjust the code with the same effect. Bootstrap or even one day is not enough. Which one do you think your boss wants you to use?

All frameworks are used to reduce workload and improve work efficiency

Flattening and front-end framework make it easier for you to learn

Is it possible to restore the knot? I want to ask