Enabled = False VS Readonly = True

Enabled = FalseVS Readonly = True
Hmmm, both of them have same function, as to disable editable operation in a property toolbox such as TextBox.

But I don't know, some of my textbox which I set the enabled = false, then I can't get the value of the textbox. I search some people said that "If we want  to pass the value we can use readonly = true, but if we wont we can just use enabled = true". Yeahh, that's right.

But why in some textbox I can pass value by using enabled = false????