Users expect pages of a website to follow a consistent structure. Certain interface elements, such as navigation menu, headers, and footers are seen in most web applications. However, it is cumbersome to repeat them in every template.
Most templating languages have an include mechanism. The contents of another file, possibly a template, can be included at the position where it is invoked. This can get tedious in a large project.
The sequence of the snippets to be included in every template would be mostly the same. The ordering is important and hard to check for mistakes. Ideally, we should be able to create a base structure. New pages ought to extend this base to specify only the changes or make extensions to the base content. ...
