Hereunder is a list of some of the terminology you are likely to hear on the Theist Helpline show:

deity / deities

The word "deity" is the sex-neutral term for a god or a goddess.  The word "deities" is the plural form, denoting multiple gods and/or goddesses.

atheism / atheist

Fundamentally, atheism is the absence of belief in deities, and an atheist is an individual who doesn't believe in any deities.
See also:  Definition of atheism (and atheist)

deism / deist

Deism is the belief that there either was at least one deity, or that said deity or deities still exist but are no longer interested or involved in any aspect of humanity, and a deist is an individual who holds views described by deism.

monotheism / monotheist

Monotheism is a specific type of theism that recognizes belief in only one god or goddess.  A monotheist is an individual who believes in only one god or goddess.

polytheism / polytheist

polytheism is a specific type of theism that recognizes belief in multiple gods and/or goddesses.  A polytheist is an individual who believes in multiple gods and/or goddesses.

Further reading:

• Definition of atheism:  https://www.define-atheism.com/
• Religions Wiki:  http://www.religions.wiki
• Stanford Encyclopedia of Philosophy (SEP):  https://plato.stanford.edu/