Depending on context, protector can be translated as:

Beschützer

Panzer, e.g. Brustpanzer - chest protector

Schutz, e.g. Gewebeschutz - textile protector

Schutzschalter, e.g. Stromschutzschalter - surge protector

Schützer, e.g. Knieschützer - knee protector

Yes, "protector" is a noun, a singular, common noun, a word for someone or something that protects someone or something.

The noun protector is a concrete or abstract noun, depending on use; for example:

A pocket protector or a splash protector is a concrete noun.

A friend and protector or a protector of the faith is an abstract noun.

Protector is a noun.

Aphrodite was the protector of the sailors.