Substantive is what by itself designates the substance itself, i.e the essence, the matter. It is a term originating from the Latin “substantivu” which means “substantial”.
Grammatically, noun is any word that names everything that exists. It's all that names beings, a everything you see, hear, feel or imagine. E.g.: home, plane, scream, music, happiness, love etc.
Any word can be given a noun. To do so, just precede it with an article. Ex.: the no is a cruel word. (noun adverb). to love you it's the to hate they know no limits. (noun verbs).
The noun can vary in gender (masculine and feminine), number (singular and plural) and degree (augmentative and diminutive).
As for the element it designates, the noun is classified as: proper (Brazil), common (city), concrete (pen), abstract (beauty), simple (flower), composite (hummingbird), primitive (car), derivative (cart).
The collective noun is all that common, even in the singular, which designates several beings of the same species: atlas (of maps), library (of books), swarm (of bees) etc.
Read about the Adjective meaning and meaning of definite and indefinite article.