HTML validate input field

1. How to validate HTML input field?
2. Where do you validate the entries in field?

How to validate HTML input field?

To validate the form using HTML, we will use HTML <input> required attribute. The <input> required attribute is a Boolean attribute that is used to specify the input element must be filled out before submitting the Form.

Where do you validate the entries in field?

On the Fields tab, in the Field Validation group, click Validation, and then click Field Validation Message. Enter an appropriate message. For example, if the validation rule is >10, the message might be “Enter a value that is less than 10.”