Installation Process of SAP Enhancement Packages

Hi All,

I am new to sap and i have to install the ECC 6 server. i just want to know what are the Enhancement Packages and what is the process to install them.

Sap note is very confusing regarding the Enhancement package.

one thing more when we install the Enhancement package Before or after the installation of Support Packs?

Please Clearify it is urgent .....

Please help??????????

Regards,