What is the difference between Red Line Drawing and As-Built Drawing?

Both Red Line Drawing and As-built Drawings shows the deviation or modification done at site during the construction which is not as per the IFC drawings. 

Red Line Drawing shows the modification done in the drawings as per the site construction and which is submitted before the As-built Drawing preparation and after getting the approval for Red Line Drawing, As-built drawing shall be prepared and submitted for approval.

If there is anything wrong so, please correct me. thanks in advance.

Red line show the daviation or alteration as per site requirements