Research and Design CSS terms


CSS Specificity is the set of the rules applied to CSS selectors in order to determine which style is applied to an element. The more specific a CSS style is, the higher point value it accrues, and the likelier it is to be present on the element's style

Specificity determines which CSS rule is applied by the browsers and is usually the reason why your CSS rules don't apply to some elements, although you think they should.


Note, that CSS precedence happens at CSS property level. Thus, if two CSS rules target the same HTML element, and the first CSS rule takes precedence over the second, then all CSS properties specified in the first CSS rule takes precedence over the CSS properties declared in the second rule

Assuming specificity is exactly the same, the order of the style declarations does matter. Styles declared later, win.


In CSS, inheritance controls what happens when no value is specified for a property on an element. Refer to any CSS property definition to see whether a specific property inherits by default ("Inherited: yes") or not ("Inherited: no")

CSS inheritance works on a property by property basis. When applied to an element in a document, a property with the value 'inherit' will use the same value as the parent element has for that property.


There are a number of CSS properties that you can use to style a site. Some examples are:

These CSS properties are great ones to use as examples, because they are all very straightforward and, even if you do not know CSS, you can probably guess what they do based on their names.


CSS values are set against CSS Properties and reside within CSS declaration block, which is a part of the CSS rule / statement. CSS allows following types of values : Integers and real numbers, Lengths, Percentages, URLs and URIs, Counters, Colors, Strings, Unsupported Values.

CSS value definition syntax, a formal grammar, is used for defining the set of valid values for a CSS property or function. In addition to this syntax, the set of valid values can be further restricted by semantic constraints (for example, for a number to be strictly positive).


A CSS selector is the part of a CSS rule set that actually selects the content you want to style.

A selector is used to specify what you are styling and assign a value to the property you want to style