Scan or peruse are two words that refer to the same action, which is to READ something carefully and thoroughly. Scanning or perusing is a process of reading something in detail, usually for the purpose of understanding it better. It is often used when reading a book or article, or when studying for an exam. It involves taking the time to READ each word and sentence, and to think about what it means. Scanning or perusing can also be used to look for specific information, such as when searching for a particular word or phrase in a document.