Understand the file structure in CodeIgniter if you want to build applications successfully.


The following picture shows the file structure of CodeIgniter


  • application – Always you will be there to code
  • system – contains the core files or system files. you don't need to change in any case
  • user_guide – user manual for CodeIgniter. you can delete this folder if you want system will not .be effected
  • vendor – this directory contains composer packages source code. The other files related to this directory are composer.json and composer.
  • index.php – This is the entry point into the application. if you want to change the name of your application folder you can use this file and also you can change the environment we will dicuss more in later

Application subdirectories



  • cache – stores cached files
  • config – configuration files
  • controller – controllers are defined
  • helpers – this directory is used for user-defined helper functions
  • hooks – used for custom hooks
  • language – used to store language files for applications that use more than one language
  • libraries – custom created libraries
  • logs – application log files 
  • models - models are defined
  • third_party – contains packages that you or other developers have built.
  • Views – all your view file into it