Question:What are dashboard functions? 

Dashboard function gives us a small problem to overcome. We want to be able to call this function from other functions in the class, as we have in the index function.

Question:What are parse functions? 

Usually parse functions convert the data from one type into another type. Example: string to number, number to string.

Question:What are debug functions? 

We should add in a debug function for ease of use. When  the  debug  function  is called , we want  to  echo  out  the  URL  of  the  last  API  call , and  the  HTTP  Status  Code.

Question:Define hooks in term of codeigniter? 

A CodeIgniter hooks feature provides a means to tap into and modify the inner workings of the Codeigniter framework without hacking the core files. The hooks features can be globally enabled/disabled by—
                                $config [‘enable hooks’] =TRUE;

Question:What is thumbnail? 

The thumbnail function will simply resize the original image to smaller so that the browsers are capable to load it fast as an icon.
$this->image_lib->resize();

Question:Why we use _remap() ? 

If controller contains a function named _remap(), it will always get called regardless of what URI contains. It overrides the normal behavior in which the URI determines which function is called, allowing us to define our own function routing rules.

Question:Write down  CodeIgniter  features? 

CodeIgniter's main features are:

 Model-View-Controller Based System
 Extremely Light Weight
 Full Featured database classes with support for several platforms.
 Active Record Database Support
 Form and Data Validation
 Security and XSS Filtering
 Session Management
 Email Sending Class. Supports Attachments, HTML/Text email, multiple protocols (sendmail, SMTP, and Mail) and more.
 Image Manipulation Library (cropping, resizing, rotating, etc.). Supports GD, ImageMagick, and NetPBM
 File Uploading Class
 FTP Class
 Localization
 Pagination
 Data Encryption
 Benchmarking
 Full Page Caching
 Error Logging
 Application Profiling
 Calendaring Class
 User Agent Class
 Zip Encoding Class
 Template Engine Class
 Trackback Class
 XML-RPC Library
 Unit Testing Class
 Search-engine Friendly URLs
 Flexible URI Routing
 Support for Hooks and Class Extensions
 Large library of "helper" functions

Question:What do you mean by web service? How many ways we build webservice? 

 Webservice:A software system designed to support interoperable machine-to-machine interaction over a network. 

There are a number of ways in which we can bulid a web service:
a.      Remote Procedure call with XML-RPC
b.     Representational State Transfer with RESTful method

Question:What are bottlenecks and what are the types of bottlenecks? 

A bottleneck is part of application that is slower than the other parts, and that is slowing down the application as a whole. Here are a number of different types of bottlenecks:
 Database
API
Bandwidth
Static
Code

Question:What do you mean by benchmarks? 

Benchmarks let us log the time it takes for a part, or multiple parts, of our application to run. Once we have benchmarked our application, we can generate a report to see the timings of our application wherever we set a benchmark. We can then seek out any bottlenecks in our application, and rectify them.