You search for key words or ideas. In most cases, you know what you're looking for, so you're concentrating on finding a particular answer. Scanning involves moving your eyes quickly down the page seeking specific words and phrases. Scanning is also used when you first find a resource to determine whether it will answer your questions. Once you've scanned the document, you might go back and skim it.
Scanning is a reading technique to be used when you want to find specific information quickly. In scanning you have a question in your mind and you read a passage only to find the answer, ignoring unrelated information