CodeIgniter is PHP Open Source php MVC framework that can help us to speed up the development of our web applications. CodeIgniter was written by Rick Ellis, rock musician turned programmer.
MVC Stands for Model, View and Controller. MVC is software approach that separate your application logic from its data and presentation.Model
Model holds our data structures.Model Class contain functions that help us to retrieve ,update and insert data in our database.View
View holds data presentation logic.View requests data from the model that it uses to generate an output representation to the user.Controller
Controller work as coordinator between Model and View.Controller takes input from the user and instructs the model and a view to perform actions based on user input.
To remove index.php from URL in codeigniter, we create ".htaccess" and place it in root directory of codeignite
you do not need to load constants anywhere,they are automatically loaded by CodeIgniter.
CodeIgniter's Hooks feature allow us to change the inner working of the framework without changing the core files.