Fields are the individual components of the Lead record, containing specific pieces of information. Your account initially contains only the basic contact fields (First Name, Last Name, Address, etc.), Which we call "General Fields."
You are then able to create any number of custom fields to supplant the basic contact information. These fields will not only hold your lead data, but will also be used in creating your forms for collecting Lead data. Administrative users and users with specific permissions related to Fields may add, delete, or edit the fields at any time, but be advised that changes to the fields can affect your forms.
To add an additional Field to your account click on the Settings tab. Off the settings tab choose "Fields" and click the link marked "Add Field." You will then be able to name the field and select the data format(i.e. Text, Number, etc.) it will use.
You can also quickly and easily create drop-down lists or radio buttons for multiple choice fields by selecting the Options data type and entering the items you wish to display.