Picklists allow you to create custom fields enabling users select values from self defined lists. In Crelate, you'll have the option to manage and create your own picklists to select as a drop down in Crelate.
To manage your picklists go to Settings>> Manage Picklists
From there, you can expand and add on a number of different categories to later select on contact, company and job record.
On a contact record you can then begin typing to pull up a list of items in that picklist.