The purpose of scanning is to find specific information. In the past, the paper edition of the telephone directory was big as a brick. If you wanted to call a friend, you had to scan from page to page to find the correct number. It was quit cumbersome, as it was back in the good old days. Thankfully, we have digital tools nowadays. However, we still scan information from time to time. We scan when we look for specific information in dictionaries, newspapers, websites etc.