If not present the default is 40. However the wrapping may not be preserved when sent to the server. The value sent to the server is the text entered in the text area. If the name attribute is the same for two or more CheckBoxes, then the value attribute of all checked CheckBoxes will be sent to the server. Only one Choice can be selected.
Size is the number of lines displayed.
They are most often used to launch client scripts that modify the value of other form elements. When the Submit button is clicked, we can see in the location bar the Query String. It's copied below for readability and comments to the right. Some values might change depending on the state of each element prior to submission. CheckBoxValue1 Both CheckBoxes were checked when this was sent.