Before we start using Bootstrap 4, let's understand a few of its common patterns
Simply put, if we don't use Bootstrap 4 and instead write web pages by hand, we have to write the HTML content ourselves (obviously), and we also have to set each CSS property one by one (another obvious statement). However, if we use Bootstrap 4, many commonly used CSS styles are already pre-written for us. We just need to be familiar with Bootstrap 4's documentation, know which class name corresponds to the pre-written CSS, and then directly apply it to the tags.