HTML
Tags we need to know: (Other tags will be introduced in the question.)
<html>
<link>
<head>
<title>
<body>
<h1> <h2> <h3>
<img>
<a>
<div>
<form>
<input>
<p>
<li>
<ol>
<ul>
<script>
CSS
Need to know In-line CSS e.g:
<h1 style=”color: blue;”>
and external style sheets.
JavaScript (Other javascript will be explained in the question.)
Input will be taken by reading values from a form
Output
Need to know:
How to change contents of an HTML Document:
chosedElement = document.getElementById(“example”);
ChosenElement.innerHTML = “Hello World”;
Write directly to the document:
document.write(“Hellow World”);
Using an alert box:
alert(“Hello World”);
Search Engine Indexing:
Search engine indexing is when web companies such as google start up a web crawler program. The program sends out spiders that travel through the world wide web along hyperlinks to each website, collecting keywords and meta data about that website to be stored in their search engine database. This data is then sorted and ordered to make search times very quick.
Page Rank Algorithm:
The page rank algorithm is an algorithm developed by google to rank web pages in an order of relevancy according to your search. There are hunderds of factors that the algorithm considers including, Domain name, Frequency of search term in web page, Age of web page, Frequency of page updates, Magnitude of content updates, Keywords in <h1> tags.
The original page rank algoritm is:
PR(A) = (1-d) + d (PR(Ti)/C(Ti) + … + PR(Tn)/C(Tn))
PR(A) is the PageRank of page A
PR(Ti) is the PageRank of pages Ti which link to
page A
d is the damping factor
C(Ti) is the number of outbound links on page Ti
For the first iteration, we assume that the page’s rank is 1 and then only after several iterations is it accurate.
Server And Client-Side Processing:
A client is any device that is connected to a service, such as a computer or a phone. Client Side Processing is when data is processed before it is sent to the server. On the web this happens in the form of a script. The web page does not communicate with the server at this point.
An example for client side processing is JavaScript on a webpage. This may be used for validation before being sent to the server.
Advantages:
- Quick execution and response times as it does not have to communicate with the server. Everything is local at this point.
- Removes potentially unnecessary load on the server.
- Removes risk of data being intercepted on the way to the server, increasing security.
Disadvantages:
- Not all browsers support all types of scripts.
- Dependant on the performance of client-side machines.
- Different browsers can process scripts in different ways so the page may look different to what the developers intended.
Computer Science Notes 