The word です is a copula or linking verb, which serves to link a noun to a predicate (information about the noun). It is similar in meaning and function to the words ‘is’, ‘am’, and ‘are,’ in English and also translated as simply ‘to be.’ There are certain conditions and rules that dictate when です can be used in sentences. Furthermore, we can conjugate it into past tense and change its formality depending on the situation.