firefox add-on vs. extensions vs. plugins

Question

I want to write scripts for firefox. It seems that firefox has different terms, like add-on, extensions, plugins. and I have a feeling they\'re not all the same. Can you sum

Answer 1

Extending the Augmentation above

Extension(s) is ment to extend the functionality of software where a plug-in is ment to solve a problem of the software (to be able to do something it wasent designed to do already).

both types extends the program abilitys, ... and i guess this is why it can be so comfusing.

An Extension can be (and often are) a(n) option from the company that made the software (Usually cost money), a plug-in can be from the company that made the software or a third party to add abilities to the software.