In computer, programming input is any data that is sent to a computer for processing. User input is input sent to a computer by the actions of a software user. In web development user input includes form-field data, mouse clicks, and other interactions by the user that is sent back to the server for processing. HTML has input field elements that are specifically designed to capture user input.
HTML form:
<form action="login.php">
<label for="username">Username:</label> <br>
<input type="text" id="username" name="username" placeholder="username"><br><br>
<label for="password">Password</label> <br>
<input type="text" id="password" name="password" placeholder="password"><br><br>
<input type="submit" value="Submit">
</form>
The form above would look something like this when displayed to the user: