title: MySQL concepts: session vs connection
body: <p>I'm a bit confused by MySQL concepts: session vs connection.</p>
  <p>When talking about connecting to MySQL, we use connection terminology, connection pool, etc.</p>
  <p>However in the MySQL online doc: <a href="http://dev.mysql.com/doc/refman/4.1/en/server-system-variables.html" rel="nofollow noreferrer">http://dev.mysql.com/doc/refman/4.1/en/server-system-variables.html</a>, it talks about session variables.</p>
  <p>They are quite similar. How to distinguish them?</p>
  <p>Thanks in advance.</p>