What constitutes a word?

Hi,I was wondering if someone could help in this regard.

More and more I am coming across words such as 圆桌,客人

At what point do we deny the word status, or do we?The characters tend to be a block of information, where do we draw the boundaries?

At first I would just Lingq everything but now as I progress I notice words are made up of two characters which if read separately mean the exact same thing, therefore I hesitate to class this as a separate word.

I usually count it if it has a deviation from the English translation, but am unsure about this.

I feel I might be looking into this too much, after all , the word counter is a motivator more than anything, but I would appreciate any help on this issue.

Thanks!