How to read and write INI files in PHP?

INI files are simple text files with a basic structure consisting of sections, property and value. INI files can be used across different platform which is a great advantage as a single INI file can be used in various versions of the same application for various platforms. INI files are used to store configurations for applications in a manner of property = value. Values can be single or one dimensional array. Also sections can be used to group same type of configurations. The last thing is comments, we can write comments in INI files. Comments in INI files starts with ; (semicolon)