Final answer:
The term for different cultural groups co-existence within the same nation-state is multiculturalism, which reflects the presence of multiple cultures living together with mutual respect and contributing to the nation's diversity.
Step-by-step explanation:
The term for different cultural groups co-existing within the same nation-state is multiculturalism. This concept reflects the presence and mutual respect of multiple cultures living together in a single country. Cultural groups can differ in terms of language, religion, and customs, and these differences contribute to the rich cultural diversity within a nation-state. Examples of this diversity might include tribal communities, ethnic neighborhoods or larger constructs like pan-ethnic groups that work to establish a collective identity without erasing individual ethnic ties. States often contain several culturally distinct groups whose language, religion, tradition, and historical experiences differ. Food, language, religion, and traditions are some elements that help maintain individual group identity within a larger society. In modern nation-states like the United States, there exists a complex tapestry of cultures resulting from different groups sharing a space, where community and identity play key roles in defining their co-existence.