### What are some differences that XHTML has compared to HTML?

#### Answer

Some of the key differences are:

* An XHTML element must have an XHTML `<DOCTYPE>`
* Attributes values must be enclosed in quotes
* Attribute minimization is forbidden (e.g. one has to use `checked="checked"` instead of `checked`)
* Elements must always be properly nested
* Elements must always be closed
* Special characters must be escaped

#### Good to hear

* Any element can be self-closed
* Tags ands attributes are case-sensitive, usually lowercase

##### Additional links

* [W3Schools docs for HTML and XHTML](https://www.w3schools.com/html/html_xhtml.asp)

<!-- tags: (html) -->

<!-- expertise: (1) -->
