There are two ways to use the <script> element
1- Put Java script code directly into the page within <script> tags.
2- Include JavaScript from an external file
. Java Script contained inside a <script> element
is interpreted from top to bottom.
The rest of page is not loaded or displayed until after
all the code inside the <script> element has been evaluated Inline Java Script Example
Java Script is light Weighted interpreted object based with first class function and the best known as scripting language for web pages but it used in many non browser environment as well.
Interpreted: No need to compile
Firstclass function: You can take a function and assign into a variable
Scripting Language: It is the way to use script run dynamically.
If you are Using Eclipse or Netbeans download click on on source code http://bootstrapdocs.com/v3.0.3/docs/getting-started/ and extract the folder copy the css, font and js folder and paste into Web Content. Then Paste below code