Clear separation for Controller and controllers required with Full Controller path

[jigneshthummar]

-I can't find difference between folder Controller and controllers folder under Catalog ( and some other ) modules its possible to merge both of them or any reason why its like that?
-more over is it possible to add full controller path as controllers class name? same like Model and Block class name?
i.e
Mage_Catalog_IndexController can be converted to Mage_Catalog_controllers_IndexController

[colinmollenhour]

The classes under Controller are meant to be abstract classes which are extended by real controllers.

[jigneshthummar]

any idea why Magento dont include controller folder name in controller class name ?
i agree we never need to make object of controller but when we rewrite controller we have to add controller file name which we rewriting. which we dont need when we rewrite block or model

[mzeis]

Organising action controllers in a controllers/ directory and omitting "controllers" in the class name originates from Zend Framework.

[colinmollenhour]

When rewriting controllers sometimes you only want to rewrite specific methods. There are probably other good reasons as well, but in general controllers are quite a bit different than models/helpers/blocks.

[magento-team]

Good question, @jigneshthummar.
You are not first, who asks about it.
@colinmollenhour and @mzeis are absoluttelly right.

when we rewrite controller we have to add controller file name which we rewriting. which we dont need when we rewrite block or model

If you say about rewritting controller via config.xml, than you don't need to specify file name there.
If you say about extending controller classes, than this is not recommended practice.

We'll add documentation page about differences between 'controllers' and 'Controller' directories in Magento Framework section.