CodeIgniter is an Application Development Framework – This framework is built on php and this framework is very lightweight.
Use of this framework you can website very for and very easily and quickly because this is developer friendly and very understandable.
You can install by downloading zip-
CodeIgniter is installed in four steps:
Unzip the package.
Upload the CodeIgniter folders and files to your server. Normally the index.php file will be at your root.
Open the application/config/config.php file with a text editor and set your base URL. If you intend to use encryption or sessions, set your encryption key.
If you intend to use a database, open the application/config/database.php file with a text editor and set your database settings.