text_field_tag placeholder rails

<%= text_field_tag 'username', nil, placeholder: 'Enter your username' %>

1. <%= ... %>: Embedded Ruby tags for embedding Ruby code into HTML.
2. text_field_tag: Helper method for creating a text input field.
3. 'username': The name attribute for the input field, used to identify the field when the form is submitted.
4. nil: The initial value of the input field, set to nil as it's empty initially.
5. placeholder: 'Enter your username': Specifies the placeholder text that is displayed in the input field as a hint to the user.