optical drive for IMAC

tried the search function first, but not finding what I need.

I have ordered a new IMAC, and in fact am switching from the PC world so I am clueless about some things.

Am looking for a basic optical drive , not for  burning but for loading software that I have that is on a cd,

Any suggestion would be appreciated. I check out Newegg website but my eyes glassed over after a  bit and they can't provide technical support.