Large documents are easier to read if they have a table of contents with links to relevant sections.
A constant is a named value that doesn't change while the program (script) in running.
If you want create a link to a document that opens a new browser window, set parameter target="_blank" of the a tag.
With CSS, you can set the style and appearance of the text.
Quite often, when creating an object it is required to set values to some properties. Fortunately, the developers of OOP took this into account and implemented it in the concept of constructor.
In CSS absolute and relative units are used to specify dimensions of various elements.
Cascading Style Sheets allow you to keep the color, text size, and other parameters in styles.
Numbered list is a list of items each having its own numbers. The style and the type of numbered list depends on the ol tag, which is used to create it.
PHP does not directly support destructors. However, you can easily simulate a destructor by calling the PHP function unset.
Style sheets can be added to a Web page in three different ways, which vary in their properties.