Differnence between Enhancement spot and composite Enhancement Spot

Hi,

I was going through several weblogs on enhancement framework, but igot stuck at one point.

Can you please tell me the differnence between Enhancement Spot and Composite Enhancment Spot in very simple term with an example.

Please also clear some terms like enhancement spot and enhancement option, Enhancement and how new BADIs are related to enhancement spots.....

Points will be rewarded!!!!

Thanks in Advance.

Regards,

Varun