Today we will learn how to use interesting custom tags to layout pages. Some friends may have this question, how can the browser correctly recognize the tags that they have defined casually?
Here we will use the namespace of the document, so what does the namespace refer to?
Everyone knows that one of the great features of XML is its scalability. You can create your own tags or use tags created by others. There is a problem here, that is, the tags you define
may be the same as those defined by others, but they each represent the same meaning. But different.
To give an analogy, for example, there are two people named Blue, one is in Classic and the other is in Tianya. If you want to find them, you can explain it like this, Tianya: Blue, Classic: Blue color so there is no confusion.
The meaning of the namespace is to tell others who this document belongs to. xhtml is the product of the transition from html to xml, and it also provides us with a namespace here.
Look at the example below, we name a prefix named blueidea, http://bbs.blueidea.com is the url used to describe the namespace. xmlns refers to xhtml namespace