The purpose of the service must be clear to users at the start of using the service. That means a user with no prior knowledge must understand what the service will do for them and how it will work.
What this means in practice
The service’s name, description and the way that it’s designed all make it clear to your user:
• What the service does
• Why the service exists
• How the service works
• Who the service is for
You’ve achieved this when
A user can understand (on its own) what your service is, who its for, why it exists and quickly understand whether the service is what they’re looking for.
How to do it
Think about what your service does for users, why it does this, how it does it and who it does this for.
Clearly communicate this to users – through things like the service name, description and even the interaction design of the service,