Basic
Part of speech: noun
Definition: A necessary commodity, a staple requirement. An elementary building block, e.g. a fundamental piece of knowledge. basic training.
Part of speech: adjective
Definition: necessary, essential for life or some process. elementary, simple, fundamental, merely functional. Of or pertaining to a base; antonym of acidic
Example sentence: Political tags - such as royalist, communist, democrat, populist, fascist, liberal, conservative, and so forth - are never basic criteria. The human race divides politically into those who want people to be controlled and those who have no such desire.
Introductory
Part of speech: adjective
Definition: introducing; giving a preview or idea of