Is it possible to add a new field in Leads, Potentials, etc.?

Is it possible to add a new field in Leads, Potentials, etc.?

I just used Zoho and I am starting to set this up and make this work. My question is, would it be possible to add a new field for Leads other than the default ones? What I would want to do is to add a "comment(s)/remark(s)" field. However, I am not seeing the field on Zoho. Instead I only have to utilize "description field" since it is the only one that is available. I already have several sheets that I imported but my "comments field" are the only ones that are not imported. Is this a workaround for this? Thanks!