Why shouldn't you rely on form placeholders alone? [duplicate]

1. Why are placeholders important?
2. Should you use placeholder text?
3. What is the difference between input label and placeholder?
4. Do screen readers read placeholder text?

Why are placeholders important?

Placeholders are frequently used to provide important input formatting instructions or are used in place of a more appropriate label element (more on that in a bit).

Should you use placeholder text?

Placeholder text can be used as an attribute for almost every HTML input type, and misguided designers and developers don't hesitate. It is tempting to provide text help for complex forms or omit input labels to improve aesthetics. However, employing placeholder text to do so causes many usability issues.

What is the difference between input label and placeholder?

Labels tell users what information belongs in a given form field and are usually positioned outside the form field. Placeholder text, located inside a form field, is an additional hint, description, or example of the information required for a particular field.

Do screen readers read placeholder text?

Assistive technologies, such as screen readers, do not treat placeholder text as labels.