hi @DhanA2
The foundations package does not include stitching. I noticed that derived fields are also not available. Both of these are key features of CJA in my opinion.
Without stitching, your data would be limited to the select person ID.
With stitching enabled, you can use multiple IDs. For example, you can create a relationship between cookie IDs when they log into the same account (account ID) within the lookback period. Thus, these multiple cookie IDs will be seen as one Person.
Without stitching, if your person ID is cookie ID, each would be seen as a separate Person. If account ID is your person ID, you wouldn't have visibility to those who didn't log in.