An INI file is a basic configuration file, commonly used by windows-based applications. It is written as plain text so any text editor can be used to read and write INI files.
The file consists of one or more sections, and each section consists of zero or more key/value pairs.
[Section1]
Key1=Value1
Key2=Value2
[Section2]
Key1=Value3
Key2=Value4
[Section3]
Key1=Value5
Key2=Value6
The INI file above contains three sections (Section1, Section2 and Section3), each section contains two keys.
As can be seen the keys does not have to be globally unique, the only have to be unique within the section.