Nouns can be divided into the following groups based on their meaning: class nouns, collective nouns, nouns of material, and abstract nouns.

Class nouns denote persons or things belonging to a class. They are countable and have two numbers: singular and plural. They are generally used with an article.

“Well, sir,” said Mrs. Parker, “I wasn’t in the shop above a great deal.” (Mansfield)
He goes to the part of the town where the shops are. (Lessing)

Nouns of material denote material:

iron, gold, paper, tea, water

They are uncountable and are generally used without any article.

There was a scent of honey from the lime-trees in flower. (Galsworthy)
There was coffee still in the urn. (Wells)

Nouns of material are used in the plural to denote different sorts of a given material.

…that his senior counted upon him in this enterprise, and had consigned a quantity of select wines to him… (Thackeray)

Nouns of material may turn into class nouns (thus becoming countable) when they come to express an individual object of definite shape.

To the left were clean panes of glass. (Ch. Bronte)
“He came in here,” said the waiter looking at the light through the tumbler, “ordered a glass of this ale.” (Dickens)
But the person in the glass made a face at her, and Miss Moss went out.(Mansfield)

Abstract nouns denote some quality, state, action, or idea:

kindness, sadness, fight.

They are usually uncountables, though some of them may be countable (e. g. idea, hour).

Therefore when the youngsters saw that mother looked neither frightened nor offended, they gathered new courage. (Dodge)
Accustomed to John Reed’s abuse — I never had an idea of replying to it.(Ch. Bronte)
It’s these people with fixed ideas. (Galsworthy)

Abstract nouns may change their meaning and become class nouns. This change is marked by the use of the article and of the plural number:

He was responsive to beauty and here was cause to respond. (London)
She was a beauty. (Dickens)
…but she isn’t one of those horrid regular beauties. (Aldington)

Collective nouns denote a number or collection of similar individuals or things regarded as a single unit. Collective nouns fall under the following groups:

nouns used only in the singular and denoting the number of things collected together and regarded as a single object: foliage, machinery.

It was not restful, that green foliage. (London)
Machinery new to the industry in Australia was introduced for preparing land. (Agricultural Gazette)

nouns which are singular in form though plural in meaning:

police, poultry, cattle, people, gentry

They are usually called nouns of multitude. When the subject of the sentence is a noun of multitude the verb used as the predicate is in the plural:

I had no idea the police were so devilishly prudent. (Shaw)
Unless cattle are in good condition in calving, milk production will never reach a high level. (Agricultural Gazette)
The weather was warm and the people were sitting at their doors. (Dickens)

nouns that may be both singular and plural:

family, crowd, fleet, nation

We can think of a number of crowds, fleets, or different nations as well as of a single crowd, fleet, etc.

A small crowd is lined up to see the guests arrive. (Shaw)
Accordingly they were soon afoot, and walking in the direction of the scene of action, towards which crowds of people were already pouring from a variety of quarters. (Dickens)