Final answer:
The structure used in the given sentences is declarative sentence structure.
Step-by-step explanation:
In the given sentences, the structure being used is the declarative sentence structure.
Declarative sentences make a statement or express an opinion. They end with a period.
Examples of declarative sentences in the given sentences include 'The term democracy refers to a government of the people, by the people and for the people.' and 'A democracy serves the needs of the people.'
Learn more about Declarative sentence structure