The niche of a species is the functional role of that species in the community that it belongs to. Species that have narrow niches (have very specific resource requirements) are said to be , while species that have broad niches (able to use a wide array of resources) are known as

Specialists and Generalists

Explanation:

Niche is the role played by an organism that how it lives in an environment

Specialists

Species that have narrow niches are called specialists and this type of niche is called realized nicheIt is narrow because of the presence of ecological barriers and is the space where a species actually lives

Generalists

Species that have broad niche are called generalists and this type of niche is called fundamental nicheIt is larger than the realized niche due to absence of ecological barriers It represents all the environmental conditions where a species is able to live or can live