Css3 Definitions


refers to the rules that are specific to a certain part of a webpage or document such as wanting to place emphasis a certain part of a document by changing the color of the text or to bold the text. The specificity can be set in any of the rules but the precedence will still be inline, embedded, and external.


determines an orderly method of which rules will be applied when there may be more than one rule that may apply to a certain section of a webpage or document. Usually the precedence will be the rule that is closest to the document. An inline rule will have the most precedence, followed by an embedded, with the external being next, the least precedence will be the rules that are established by the host provider.


refers to when a rule is set for instance in the main body it will apply to all elements that fall within that section, text size, color, and line spacing to name a few. Unless a specific rule is used to put emphasis in a certain part of the document.


Is the part of the declaration that appears before the : to describe what element you are making the rule for. (text-align, font-family, border, color, etc,,,)


the part of the declaration that appears after the : to describe the value you are placing on the property, ( center, times new roman, solid 2px black, red, )


is the part of the declaration that will tell you what element you are targeting when making the rule. It is before the bracket { in the line. There are several different selectors used in css.

Element selector

selects the element by its name (nav, body, header, footer) and will affect everything within that element.

Class selector

will affect everything with in a class and the selector is designated by a (. period) before the name of the element and will need to be called out (class=" ") in the HTML section where it is needed. This selector can be used when ever needed within a document.

ID selector

this selector is designated before the name with a # container before the name of the element being selected and will also need to be called out on the HTML section (div id = "container") this selector can only be used once per page.


this selector is not called out in the HTML section it is added to an anchor element and has a : followed by a keyword (a:hover, a:visited) used when wanting to let people know that this is a link to another page or website.