Field Label: It is the label of custom field

Extra Information: It is a description below the label.  You can provide information or instructions about this field.

Personal Information: Set whether custom field is accepting personal information of user. e.g. mobile number, address, etc.

Field Type: Text Field, Drop Down, Checkbox, Radio Button, Textarea, Date, Date Time, Time, URL – accept and validate URL, Email – accept and validate Email, Number Only – accept and validate number only, File Attachment

Width: How it shows in the default task form

Character Limit: Limit number of characters

Visibility: Show the field based on Categories or Priorities