The technology world is full of acronyms, so many that the uninitiated may not understand what is being discussed, let alone how to implement the software or programming languages they are used to describe. Compounding matters is the fact that computers, operating systems and other technologies are constantly evolving and changing, making it necessary for even the most experienced of developers to continually focus on learning the latest techniques. One such area that both experienced developers and new designers should focus on is the difference between HTML and XHTML.
Both XHTML and HTML are mark-up languages. These are the programming languages that create the form and appearance of a website. The difference is in how they are used and implemented. Hypertext Markup Language (HTML) utilizes Standard Generalized Markup Language (SGML) to allow a developer to use attribute minimization and to omit tags. Extensible Hypertext Markup Language (XHTML) utilizes Extensible Markup Language (XML). This programming language does not permit the user to omit tags or attribute minimization. What XHTML does do is provide a sort of shorthand for elements that are empty which HTML does not.
Both HTML and XHTML are used in conjunction with CSS. Most developers note difference in three primary areas: properties of the root element, optional tags and case sensitivity. It is important to note that there are others who note a more elemental difference: that HTML is the predecessor of XHTML and is therefore inherently better. Of course this distinction is based on the belief that newer is always better.
Finally, some developers notice a compatibility issue while others note no compatibility problems. It is a good idea to check any new development for compatibility to ensure that this is not the case. Determining which programming language to use, XHTML or HTML, may be nothing more than a matter of opinion.