Once you have successfully installed and started MySQL, you need some sort of way to interact with it. Whereas mysqld is the MySQL server that manages all the data, you need a client application that will talk to mysqld. The most common way to interface with mysqld besides using a programming language is to use the mysql client(or mysql monitor, as it is also called). This application can be used to connect to mysqld running on the same machine, or even on another.
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