CRM contact identifier

CRM contact identifier

Is it possible to add a category, or a tag, to a CRM contact so you can sort names by relevant interest and create an email list for marketing or invitations?
We have a Zoho Creator list of email names and created a List to assign them to certain categories.  We'd like to be able to do that in Zoho CRM so we don't have to create duplicate entries.

Thanks for your help!
Mary