6. What is an HTML form and what elements can it contain?

An HTML form is an element used to collect user input and send it to a server. Forms can contain various input elements such as text fields, buttons, checkboxes, and more.

Form elements:

1. <input type="text"> - A text field for entering short text data.
2. <textarea> - A text area for entering longer text data.
3. <select> - A dropdown list for selecting one of many options.
4. <button> - A button for submitting the form or performing another action.
5. <input type="checkbox"> - A checkbox for selecting or deselecting an option.
6. <input type="radio"> - Radio buttons for selecting one option from a group.
7. <input type="submit"> - A button for submitting the form.

Example of an HTML form:

<form action="/submit" method="post">
    <label for="name">Name:</label>
    <input type="text" id="name" name="name">
    <br>
    <label for="message">Message:</label>
    <textarea id="message" name="message"></textarea>
    <br>
    <input type="submit" value="Submit">
</form>