The term Gender is derived from a Latin word genus (meaning kind or sort). It tells us about the sex of the noun.
Noun can be categorized into Male and Female.
A noun referring to Male counterpart is called masculine gender.
A noun referring to Female counterpart is called feminine gender.
For most of the Nouns we have distinction of Male and Female. For example, Human Beings have two genders- Boy, Man, Gents for Male and Girl, Woman, Ladies for Female.
This type of distinction is valid for most of the animals on earth.