Databases and Web search engines may include features which allow you to focus or refine your search.  If you understand the concepts and terminology of these features you can search any database or Web search engine more efficiently and effectively.

The following are common search features:

 
• Help
• Controlled Vocabulary and Uncontrolled Vocabulary
• Boolean operators (and, or not)
• Truncation
• Field and cross-field searching
• Limiting or stringing searches (date, language, format, etc.)
• Phrase searching
• Proximity searching