Readonly and disabled

How to make the content in input read-only, that is, the user is not allowed to change the content.

<Input type = "text" name = "input1" value = "China"/>
<Input type = "text" name = "input1" value = "China" readonly/>
<Input type = "text" name = "input1" value = "China" disabled/>
We recommend that you do not use disabled. Otherwise, you will not be able to retrieve the value.

<Input type = "text" name = "input1" value = "China" readonly = "true"/>
<Input type = "text" name = "input1" value = "China" readonly/>
Differences:
1. disabled -- cannot be edited at all, and cannot be copied.
2. readonly -- not editable, but can be copied.
3. Readonly is only valid for input (text/password) and textarea, while disabled is valid for all form elements, including select, radio, checkbox, And button.
4. After a form element is disabled, when we submit the form in POST or GET mode, the value of this element will not be passed out, while readonly will pass this value out.

Similarities:
Make input uneditable.