HTML: HTML (HyperText Markup Language): HTML is the most widely accepted language used to build websites. It is the main structure of a website. It builds tables, creates divisions, gives a heading message (In the title bar of programs), and actually outputs text.
XHTML (eXtensible HyperText Markup Language): : XHTML is extremely similar but follows the rules of XML. The main differences between HTML and XHTML are the case-sensitivity, the need to use closing tags for all tags, the need to use quotes around all attribute values and that all attributes must be in lowercase as XML requires. Special characters between tags need to be replaced with its code equivalent. Declaring the correct doctype (first line in source code) and language (in meta tag in the head of the source code) is required.
XHTML is used to be compatible with XML programming. Following the rules now would make it possible to include XML programming in the future. It is not difficult to change HTML pages to XHTML, but it can be time-consuming. Finding all line breaks and images to include closing tags, converting any uppercase to lowercase and any other incompatibility can be a nuisance. Using a find and replace program can allow you to edit your code faster, but you still have to reupload all those changes. It is recommended that programmers try to remember these rules to comply with W3C recommendations, so the web pages appear correctly in most browsers.
When should you be concerned with XHTML instead of just plain HTML? If the website will contain a catalog of items as in an ecommerce site, the site accesses a database, the site accesses information from another source that uses a different programming language or the site is expected to grow and exist for many years. XHTML is used when referring to XML files used for RSS feeds, some music players, some image galleries and many more applications.
XHTML is the same as HTML, except it has a cleaner syntax. XHTML uses the same tags as HTML, so people who know HTML know messy XHTML.
Some new rules are followed in XHTML like:
- XHTML elements must be properly nested.
- XHTML elements must always be closed.
- XHTML elements must be in lowercase.
- XHTML documents must have one root element.
- In HTML, some elements can be improperly nested within each other, like this:
<b><i>This text is bold and italic</b></i>
- In XHTML, all elements must be properly nested within each other, like this:
<b><i>This text is bold and italic</i></b>
Sample HTML code of .aspx file
<title>The Professionals Point</title>
Here we write code for designing the page.