Words used by an individual or a culture for self-expression communication are commonly referred to as?

Words used by an individual or a culture for self-expression and communication are commonly referred to as vocabulary.

Here's why:

* Vocabulary refers to the set of words known and used by a particular person, group, or language.

* Self-expression and communication are the core functions of language, and words are the building blocks of language.

While other terms like lexicon or word bank are also related, vocabulary is the most common and widely understood term for this concept.