Some web pages give you the ability to type in your name, email and a question. Other web pages are designed for you to type in your credit card information to make a purchase.
Any page that gives you the ability to type is called a "form." The most common form is on a Contact Us page. You don't want to post your email address directly on a website because an email bot will find it and send you spam email.
Instead we put a simple form on the Contact Us page. Typically the form requests the visitor's name, email address, phone number and some way to ask a question. When the person clicks the [Submit] button the information is gathered and emailed to you.
Other types of forms you may find include Email Signup Form, Opt-In Form and a Discount Certificate Request Form.
One last point I need to randomly cover right now. You need to learn how to read emails that come from your website. Even the worst quality websites will generate emails at least once every week. So if your forms are not sending you SOMETHING, please investigate why.