Definition
A countable noun (e.g ship) can be singular or plural. We can count ships. We can say a ship/one ship or two ships.
Here are some examples of countable nouns.
We could see a ship in the distance. Claire has only got one sister. I've got a problem with the car. Do you like these photos? I'mgoing out for five minutes.
An uncountable noun (e.g. water) is neither singular nor plural. We cannot count water. We can say water or some water but NOT a water or
two waters.
Here are some examples of uncountable nouns.
Can I have some water? Shall we sit on the grass? The money is quite safe. I love music. Would you like some butter?