Nouns are naming words for people, animals, places, things, and qualities. In fact, they name everything around us including those that are invisible (wind, gas). A noun can be recognized by the determiners - the, a, an, some, this, etc - that come before it.
There are different types of nouns. There are common nouns, proper nouns, concrete nouns, and abstract nouns. A common noun names every person or thing that belongs to the same group. A proper noun is a name of a particular person, animal, place, or thing. A concrete noun refers to a material object that we can see and touch. An abstract noun is something we cannot see or touch (love, anger). We use it to refer to things that are not concrete objects such as quality, idea, condition, etc.
Nouns can be singular or plural. We use a singular noun for one person, animal, place, or thing. For two or more people, animals, places, or things, we use plural nouns.
There are countable nouns and uncountable nouns. Countable nouns are things such as books, cars, and houses, and we can count them. Uncountable nouns such as milk, water, and flour are things which we cannot count.
We use a collective noun to indicate a group of people or things.