What is the grammatical classification of the following statement?

This is a metaphor. It’s also a Shakespeare quote. It comes from his play “As You Like It”, Act II scene VII. “As You Like It” is a play about two girls who have grown up together. The father of one of the girls had been banished, but the daughter had been allowed to stay. When the daughter incurs the other man’s displeasure, she is also banished. Hilarity ensues.

However, this particular phrase is a metaphor. A metaphor, for those still learning English, is a phrase that compares two things without the use of “like” or “as”. The word “is” will typically denote a metaphor since it is a direct comparison. It typically gives one thing the attributes of another.