Forms are elements used in web development to collect data from users. They are usually presented as a page with input fields, checkboxes and radio buttons that allow the user to fill out the form and submit it. Forms can be used for collecting information like user names, passwords, contact information, payment details, and other data. Forms can also be used to submit queries to databases, send emails, or even store data in a database. By using JavaScript, forms can be created to validate data, provide feedback to the user, and create interactive experiences.