Noun is the name of a person,place,animal,things,etc.
Person - Boy, Girl, Ram, Sita, etc.
Place -Village, Town, Delhi, India, Asia, etc.
Animal - Cow, Ox, Hen, etc
Things - Pen, Shirt, Milk, etc

Types of Nouns 

1. Proper Noun 
2. Common Noun
3. Collective Noun
4. Material Noun
5. Abstract Noun
Proper Noun - 
Proper Noun is the name of a particular person, place or thing.
eg- Ram, Delhi, India, Sunday,etc.
Common Noun - 
Common Noun is the name of the group of a person, place or thing.
eg- boy, girl, village, city,etc.
Collective Noun - 
Collective Noun is the name of similar person, place or thing.
eg- army, herd, crowd, association,etc 
Material Noun - 
Material Noun is the name of substances that cannot be counted but are measured and weighted.
eg- Gold, Silver, Iron, Water, etc.
Abstract Noun - 
Abstract Noun is the name of the feelings and thoughts of human beings.
eg- Love, Honesty, Kindness, etc.

Countable and Uncountable Nouns

Countable Nouns - 
Countable Nouns are those nouns which can be counted.
eg- Pen, Dog, Tree, etc.
Countable nouns can have plural form.
eg- Pens, Dogs, Trees, etc.
Before Singular Countable Nouns 'A/An' must be used.
eg- a boy, an apple, etc.
Uncountable Nouns -
Uncounatbe Nouns are those nouns that can not be counted.
eg- Gold, Water, Love, Music, etc.
Uncountable Nouns cannot have plural form.
Befor Uncountable Nouns there no use of 'A/An'.