Cadet

Cadet was a rank which was used at Starfleet Academy to denote students in training to become Starfleet officers.
Becoming a Starfleet cadet was a difficult process and required a significant amount of academic achievement while completing primary education. Academy entrance standards were particularly high although different tracks had different specific requirements. The phyiscal requirements for placement in the Security school were the highest while Science and Engineering had the strictest science and math requirements.
In addition while at the academy students must maintain both a passing grade point average across all their class as well as following the ethics and behavioral guidelines applied to all Starfleet personnel. In addition to course work and lab work, many academy classes offer field work and cadets can be temporarily stationed on Starfleet ships to get first-hand training on what it takes to become an officer.
All Federation citizens are eligible for appliation. Applicants who are not part of the Federation must get a Starfleet senior officer to sponsor them. In addition there are several refugee and foster care scholarships that are extended during a crisis. For example after the Cardassian occuption of Bajor, many Bajoran refugees were granted the right to apply to Starfleet Academy.