To make a web page, we need to use three tools, html, CSS and javascript. The semantic UI is a very useful CSS tool. In fact, you can think of it as a good cosmetic because it looks better and easier than the normal CSS interface. Nowadays, whether a tool is good or not depends to a large extent on whether it integrates many useful modules. The semantic UI is such a tool that integrates a lot of beautiful UI modules to make web page production more efficient and beautiful.
CSS is still a better way if we are pursuing personalization and flexibility, because our ideas will not be bound by tools. Indeed, the disadvantage is that the speed of making web pages will be slower. In fact, we always need to choose between efficiency and personalization. However, to create a static web page by using the semantic UI is simply beyond our imagination, only requiring fewer code to finish it.
The biggest feature of the semantic UI is just like its name. You can make your web page literally. If you want a button, just write the ui button, you want it to turn red, just write ui Red button, do not need to know that red is actually #B03060. We describe the page we want, the semantic UI will display the page. The language we use to describe is called adjectives here, for example: item, very large, fixed menu, inverted, etc. However, this description is limited. If we say that we want a menu that frees itself, then it will not react, and will not give an error, just ignore it. In fact, we can write an adjective like this to its lexicon, because the semantic UI is open source, so you can add your own modules.