Meaning – The term mandatory fill field, refers to a field a user must fill in completely or leave blank.
Required or mandatory fields are form questions that must be answered by the user before the form can be submitted. The opposite of required fields is optional fields. And this is where users can choose whether to answer the form questions or not.
Usually, when there is a form that has both mandatory and non-mandatory fill fields, the designer must ensure that the mandatory fill fields are marked with an asterisk so that the user knows that the field must be filled in order to successfully submit the form to the website or the organization.
Example of usage – “When she was filling the entry form for the company interviews, there were some fields marked with an asterisk, which meant that those fields had to be filled compulsorily, in order to submit the form for further processing.”