The stakeholder who represents the needs of the people at the operational level that will use the solution that is delivered.
The end-user is the person who will actually be using the solution on a regular basis as part of their day to day work, once it has been released the project team.
The end-user is often at the operational level of the organization, meaning that they understand the details of how the business functions on the ground.
As a business analyst, you must clearly understand the processes that end-users go through to perform their work to make sure you can clearly articulate their user needs within your requirements and specifications.
As part of your stakeholder analysis, you must identify the best representative end-users for your project because they will have a big influence on the requirements for the solution, which determines the solution outcomes that all end-users will have to live with.