web browsers

The most common web browsers are Google Chrome, Mozilla Firefox, Internet Explorer, Opera, and Safari (MAC). A web browser is a software application which is used to access sites and information on a network or the World Wide Web. This information is identified by a Uniform Resource Identifier, commonly know as a URI or URL address, and may include data such as web pages, images, video, music.  A browser allows the user to navigate the web (or network) in order to retrieve content (info/data).


When browsing the web, the most common functionality of the browser it to retrieve and present html documents as web pages. HTML documents (or pages) consist of HTML tags which identify HTML elements. For example, this is a paragraph element defined by a paragraph tag within HTML <p>This is a paragraph of text.</p>. HTML tags require and opening tag <p> and a closing tag </p> – a forward slash signifies a closing HTML tag.  The browser does not display HTML tags, it uses them to determine how to display the elements to the user.

The following html code:


          <h1>Hello world!</h1>
          <p>I have something to tell you.</p>


Would be displayed as:

Screen Shot

Cascading Style Sheets or CSS take the delivery of HTML content one step further.  If HTML allows you to describe the document content, CSS allows you to define how to display that content.  This allows developers to create a style document which will globally control the display of HTML elements like changing the color of text.  The paragraph tag (<p></p>) can have a style assigned to it through CSS. 

This text is RED

The above RED text HTML might look like this <p class=”red_text” >This text is RED</p>, the HTML tag has the added CSS class “red_text” assigned to it.  The style is defined within a separate document or style sheet and would look something like this:

.red_text {
color:# FF0000;

 Web colors are defined by a hexadecimal value of RGB (red, green, blue), FF0000 equals rgb(255,0, 0).

CSS allows all the elements of a website to be styled and fashioned to a design layout.  The relationship between CSS and HTML is important because each web browser interprets CSS slightly differently.  A web standard for browsers to follow is in place thanks to the World Wide Web Consortium (W3C), but adherence to this standard is voluntary.  Website developers must take this into account and adapt their CSS rules accordingly.  This discrepancy between the way browsers interpret CSS accounts for differences in the display of web pages between browsers.

To learn more about HTML and CSS you can visit w3schools.com