です is a copula (a word used to link the subject of a sentence with a predicate). It shows that something is or isn't something else. It is one of the very few irregular forms in Japanese. です can act like the English "to be" (you know; is, am, are...) in the sense that です is used to explain who or what something or someone is. It is also used when equating one thing with another.
Let's take a look.
ゾウ は 大きい です。
|Romaji:||zou wa ookii desu.|
|Literal:||elephants (topic particle) big are|
|Natural:||Elephants are large.|
これ は ねこ です。
|Romaji:||kore wa neko desu.|
|Literal:||this (topic particle) cat is|
|Natural:||This is a cat.|
Most of the time you want to use the "to be" verb you will use です. Later we will