How to reformat HDD alongside SSD?

Sorry if the title is unclear! I'm only just getting started on this.

On to the main topic, I have a 240gb SSD which I plan to install macOS onto alongside Windows. I also have a 1TB HDD where I would like to install all my files and applications associated with macOS.

Would I have to reformat the hard drive and use some sort of partition?

Apologies if my explanation is a bit hazy. I'm pretty confused about this myself.

Thanks in advance for the help!