Flexbox basics and terminology
Before we go too far, we should define a few Flexbox basics and some terminology that I'll use throughout the chapter. Every Flexbox layout is dependent on an outer container. As we move through the chapter, I'll refer to this container as the parent. Within the parent container there will always be a collection of boxes or blocks. I'll refer to these boxes as children or child elements of the parent. Why don't we start by talking a little bit more about why you would want to use Flexbox? The main purpose of Flexbox is to allow for the dynamic resizing of child boxes within their parent container.
This works for the resizing of both width and height properties on-the-fly. Many designers and developers prefer this technique as it allows for easier layouts with less code: