A coordinating conjunction, also called a coordinator, links parts of a sentence. This could be two independent (main) clauses, two noun phrases, adjectives, adverbials etc of equal importance.

They include: for, and, nor, but, or, yet and so,

There's a mnemonic for remembering them: FANBOYS.

For example:-

It was cold. I wore a coat.

Both sentences are valid on their own, but they can be written so that they're obviously linked; "It was cold, so I wore a coat."

The three most used coordinating conjunctions are and, or, and but.

The coordinating conjunction and usually expresses addition or combination.

For example:-

I attended the meeting. + My friend attended the meeting. = My friend and I attended the meeting.

The coordinating conjunction but expresses a contrast.

We were tired. + We were happy. = We were tired but happy.

The coordinating conjunction or expresses choice.

For example:-

Would you like tea? + Would you like coffee? = Would you like tea or coffee?

There are two negative coordinating conjunctions: neither and nor.

For example:-

She spoke neither German nor French. (Here, "nor" is part of the "neither ... nor" construction).

!Note - nor, for, and so can only join independent clauses.