HTML and Case Sensitivity
HTML is not case sensitive. This means that you can write your HTML tags and attributes using any combination of uppercase and lowercase letters without affecting the rendered output. For example, the following three lines of code will produce the same result:
<h1>Hello, World!</h1> <H1>Hello, World!</H1> <h1>HELLO, WORLD!</h1>
However, it’s crucial to maintain consistency in your HTML code to make it more readable and maintainable. The widely-accepted convention is to use lowercase for all HTML tags and attributes.
XHTML and Case Sensitivity
XHTML, a more strict version of HTML that follows XML rules, is case sensitive. In XHTML, all tags and attributes must be written in lowercase. Failing to do so will result in an error. If you’re working with XHTML, ensure that you follow the case sensitivity rules to avoid issues.
CSS and Case Sensitivity
CSS is not case sensitive. However, when dealing with CSS, it’s essential to consider the document language you’re working with, such as HTML or XHTML. If you’re working with an XHTML document, you should maintain consistency by using lowercase for your CSS selectors, properties, and values.