Countable or non-countable?
The main difference between count and noncount nouns is whether you can count the things they refer to or not.

Count nouns refer to things that exist as separate and distinct individual units. They usually refer to what can be perceived by the senses.
ex. table, chair word

Noncount nouns refer to things that can't be counted because they are thought of as wholes that can't be cut into parts. They often refer to abstractions and occasionally have a collective meaning (for example, furniture).
ex: weather, furniture, warmth

REMEMBER: One of the main differences in usage between the two types of nouns is that countable nouns CAN be counted - "Two apples, three beds" but non-countable nouns CANNOT be counted - two pieces of furniture (NOT "two furnitures"!)