As shown below:
captcha = CaptchaField(label = u'captcha')
captcha = CaptchaField(verbose_name = u'captcha')
label is the field that will be displayed if it is in a form.
verbose_name is not displayed in the form, it's just a description.
Additional knowledge:Role of django models verbose_name
First, verbose_name is the name of the corresponding display in the background, look at the figure
The corresponding backend fields are shown in the figure
Above this in django form of label and verbose name of the difference between the description is all I share with you, I hope to be able to give you a reference, and I hope you support me more.