- To hightligh text you should use the tags <span> or <div>.
<span> should be used for formatting words or characters. It is also called an inline-element
<div> should be used for formatting of blocks of texts. It is also called a block-element.
- Inside these tags you can use the attributes id or class.
Id guarantees to have a unique value over the document. It can therefore be of special importance as a style sheet selector, and can be addressed with a preceding '#'.
Classes can appear more than once.
If a style is meant to lend a specific visual effect to an element such as bold, that effect should be part of the name. If the style describes a structural part of your layout, such as a heading, the name shouldn't refer to any specific visual aspect within the style.