Search for files in ubuntu

How do I search for files in ubuntu? 1. whereis file name www.2cto.com features: fast, but fuzzy search, for example, find # whereis mysql, it will put mysql, mysql. ini, mysql. * All directories are located. I usually use this command for searching. 2. find/-name file name features: accurate, but slow, high resource consumption, for example, I want to find php. the exact position of ini requires # find/-name php. ini 3. the best and fastest method is recommended for locate file names. note: If you use this command for the first time, you may need to update the database. Just execute the command as prompted.