how to extract data from CRM datasources ?

Hi,

We have a requirement to extract data from CRM datasources. I just want to know is it similar to the ECC datasource extraction or is it something different ? I mean do we have delta, LBWE, SM13 and all that setup table filling in CRM source system as well ? Please give me some brief idea about the data extraction and some high level picture for CRM DS.

Thank You

DR