Feature Interaction Defects:
These defects occur due to incorrect description of how the feature should interact.
It includes how the user should interact with specific features.
For example ; if we take an ATM system if you want to transfer money to your friend through paytm or anything if the balance in your account is zero but it allows you to send money.
How can you send money if you do not have a sufficient balance?
So like this we can specify the interaction details,if the balance is not sufficient it may display a message that “insufficient balance”
If we give the correct interaction details that message may be displayed.
Interface Description Defects:
These types of defects occur in the description if we not specify how the target software is to interface with the external software,users and hardware.
For example;in the ATM system after inserting the card we may present the screen to the user in an understandable way.
The screen should contain a welcome message and instructions for the next step.
And the selection of the language based on the user's choice.
"These are the defects that are in the requirements/specifications defects phase."