Even though at first glance the words AddIn, AddOn, And Plugin give the same meaning, there are some differences between them. Could anyone explain to me the subtle differences between AddIn, AddOn, And Plugin?

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    Why is this question down voted? Jun 1, 2011 at 5:49
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1 Answer 1


A plugin for one particular software would make it possible for the software to be compatible with the rest of the applications around. Typically the word plug in is used for third party applications.

Ex: Flash plugin is required for a browser to play videos. Meaning, the plugin's main purpose is to make the browser compatible to work with third party flash applications.

On the other hand addon is more like an extension to the software itself, more like a supplement to the original.

Ex: Google dictionary is an addon to firefox that extends the functionality of the browser to be able to find meanings for a word within a webpage. This is more like an added functionality.

Addin I believe, is just an alternative name for plugins. As far as my knowledge is concerned, You get to see this word only in the Microsoft terminology.

Ex: An add-in for excel to display graphs.


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