Members of humanity who have, or who are directly descended from genetically engineered, perfect individuals.
These represent the best humanity can make - intelligent, physically fit, resistant to disease etc. Obviously they are the best suited to important jobs like the military, judiciary and political leadership. (Non-perfect, 'naturals' do the other jobs - but they're happy.........).

The legal definition of Perfect is, for most governments, someone whose genome is within 1% of the Perfect Human Genome Template. Everyone else is a Natural.

See also Genetic segregation