One of the important concepts of the template engine is precompilation. Basically, all template engines use some regular expressions to replace the tags with data. Since regular expressions are very costly in terms of processing, the templates are converted to functions and these functions can be used many times with less processing power. This is called precompilation.
We can see this precompiled template (function) by using Firebug (see Figure 4).
The following function is created by using Underscore for the template ‘Hello MBA students’.