The document defines different types of nouns including common and proper nouns, countable and uncountable nouns, and singular and plural nouns. Common nouns refer to general people, places, animals or things while proper nouns refer to specific ones. Countable nouns can be counted and pluralized while uncountable nouns cannot. Singular nouns refer to a single item and plural nouns refer to more than one. Examples are provided for each type of noun.