Definition of Proof reading:
Careful reading (and rereading) of a (yet to be finally-printed) document, to detect any errors in spelling, punctuation, or grammar. It may also involve checking of different elements of a layout (such as headlines, paragraphs, illustrations, and colors) for their correct dimensions, placement, type, etc. Every author knows that (despite the spelling checking abilities of modern word processors) a human proof reader is indispensable. Also called proofing. See also editing.
Meaning of Proof reading & Proof reading Definition