Change Documents

There are changes happening in SAP system all the time. Be it Master data related changes or Transaction related. Wouldn't be nice if there is a way to see all the changes done to different objects in the system?
That is where 'Change Documents' come into picture. CDHDR and CDPOS contains information of all change documents in the system.

Tables
CDHDR : Change document header
CDPOS :  Change document items
TCDOB : Objects for change document creation

Std. Program :
RSSCD100 : Displays Change Documents

TCode 
SCDO : Change Change Document

Reading CDHDR and CDPOS Tables

Object Class

The values in this field are pre-defined values which SAP has assigned to different objects like Material, Equipment, Asset, Sales Order changes etc.

The Object class values can be found in table TCDOB.

For example

Sales Order has Object Class 'VERKBELEG'.
Go to TCDOB and give the table name where the object is found and it gives the corresponding Object class needed to read the table.
Same object class is present for different tables which are of same category.

Object ID
This field has the actual values of the object , like Material number = '000MAT001' etc.


Process
Whenver a change is done , a change document number is created for the change. CDHDR has the change document number header details and CDPOS the item level details.

Note
Not all changes, like some text changes trigger a  change document.

Helpful Links
https://blogs.sap.com/2012/02/13/change-documents-for-sap-objects/