Nouns are identifiers of objects. They also act as descriptors of concepts. A noun is the subject of a sentence, with the sentence structure based on references to it. Sentence structure treats all nouns and objects as specific modifiers. A noun can be referred to using 'the' as the indicator.
Nouns may be specific or abstract:The tree
The pine tree
Examples of nouns
'The': appliance, carrot, duck, building, road, arch, screen, camera, camouflage, table, rock, concept, status, reason, role, thought, smile, fire, water, earth