Final answer:
Students at SDSU use Student Email, WebPortal, and Blackboard accounts.
Step-by-step explanation:
The three accounts that students use while attending SDSU, where they enter "one username, one password" are Student Email, WebPortal, and Blackboard. The Student Email account is used for communication with faculty and peers, the WebPortal is used for accessing personal and academic information, and Blackboard is the online learning management system for course materials and assignments.