Differences between dynamic calc & store and dynamic calc only

Dynamic calc & store:
The data associated with the member is not calculated until requested by the user, and then calculated data will be stored.
Again user request for data, if there is any change in data values then only calculates otherwise it displays the before saved value.

Dynamic calc only:
The data associated with the member not calculated until requested by the user, and  then discards the value.
Every time when user request  for it, it calculates the data without changing data values.

Comments