Cascading Style Sheets (CSS): Styles sheets define how HTML elements are to be displayed. In short Cascading Style Sheets is referred as CSS. It controls the appearance of multiple HTML pages by just including one single external style sheet. External style sheet (CSS) enables developer to change the appearance and layout of all the pages in their WebPages by just editing one single CSS file. For storing external style sheets CSS files (“. css” extension) are used. One can use ‘class’ or ‘id’ tag for CSS.
But the difference between ‘class’ or ‘id’ is that an ‘id’ is applied to a unique object, there can not be two same ‘id’ within a webpage. But a ‘class’ can designate several identical objects. For example below code 1 is possible for ‘class’ but 2 can not be used for ‘id’. 1. <div class=”test”></div> <div class=”test”></div> 2. <div id=”test”></div> <div id=”test”></div> So in case one wants to use to bold several short selections of text in his/her HTML document, he/she uses ‘id’ tag. The three ways by which style can be added in HTML document are: 1.
External style sheet 2. Internal(embedded) style sheet (inside the <head> tag) 3. Inline style (inside an HTML element) In terms of priority when HTML document displays, it first looks for Inline style, than for internal style sheet (inside the <head> tag) and at last include External style sheet which is CSS. References: Goetter, R. (n. d. ). What is the difference between a class and an id? Retrieved on 29 July 2007 from <http://tutorials. alsacreations. com/id_class/> CSS Tutorial available at <http://www. w3schools. com/css/css_intro. asp> accessed on 29 July 2007.