How itr is processed?

CPC is Centralized processing Centre at Banglore, where all Income Tax Returns filed online are processed by computerized Systems. They are not processed by some jurisdictional AO. However, after processing, if some demnd arises then case may be transferred to jurisdictional AO.  

In that case, Whats the role of the Accessing Officer.

If all ITR are processed in the CPC. AO will only do only scruitny assesment?

I thought When Someone does efiling - Computer Processing through CASS is done on the ITR to indentify it everything is okay. In case CASS detects some issue with ITR - It is automatically sends notice to the person who has filed the ITR. Other wise the ITR  goes to Accessing Officer who is sitting in your city. He will do manually scruitny & Processes your ITR.

But, you seem to say that all the ITR is processed by CPC and not by the AO sitting in your city.

it goes only to  him when some demand or some issue arrises.

Can anyone comment on this please.

Same question here. When AO comes in picture?