Final answer:
The distinction between the terms 'shall' and 'should' in a user requirements document is that 'shall' implies a mandatory requirement, while 'should' implies a recommendation or suggestion.
Step-by-step explanation:
The distinction between the terms 'shall' and 'should' in a user requirements document is that 'shall' implies a mandatory requirement, while 'should' implies a recommendation or suggestion. In other words, 'shall' indicates something that must be done for the system to function correctly, while 'should' suggests that it is advisable but not essential. For example, a user requirements document might state that the system shall encrypt sensitive data to ensure security, while it should provide an intuitive user interface for ease of use.