The stakeholder who’s business needs must be addressed by the solution that the business analyst is helping deliver,

The customer is normally the person on the business side of the organization who is sponsoring the initiative you’re working on.

They are often at the leadership level and may not directly provide input into the user-level business requirements or solution specifications.  As part of your stakeholder analysis, the customer will often identify the operational level subject matter experts and end-users that you will need to consult for your user-level requirements analysis.

As a business analyst, you must clearly understand the challenges and needs that the customer has and make sure that the solution delivered satisfies the agreed-upon business objectives of your customers.