User License is the User Management term that is best described by this definition: "Item assigned to a User that determines the functionality that they can access across the Salesforce ecosystem". Role is a User Management term that controls data visibility and reporting hierarchy within an organization based on users' positions. Profile is a User Management term that defines what users can do within an organization based on their job function and responsibilities. Username is a User Management term that identifies users when they log in to Salesforce. References: https://help.salesforce.com/s/articleView?id=sf.users_def.htm&type=5