phpMyAdmin is a feature-rich tool written in PHP, which will give you total control of a MySQL database. You can do practically anything - create fields, rows and tables, erase them or modify their content, export or import a whole database or just a specific part of it, and execute MySQL commands. The tool is irreplaceable in case you would like to switch web hosting providers, simply because you can conveniently create a full backup of a database in different formats (SQL, CSV, XML). You'll end up with one file that contains the entire content of the database, so you can download it from the present provider, upload it to the hosting server of the new one and import it via the same tool on their end. Your site shall look exactly the same, because all script applications store their content inside a database. With phpMyAdmin you could also easily search and replace content material of your choosing across the entire website - a word, an expression or a link, for example.