title: what is userDn and base in LDAP terminology
body: <p>I want to authenticate a user in <code>LDAP</code> using <em>spring</em> in java. I found that for configuration of <code>LDAP</code> with <em>spring</em>, I need <em>urls</em>, <em>userDn</em>, <em>password</em> &amp; base values like shown below:</p>
  
  <pre><code>urls=ldap://127.0.0.1:389
  userDn=cn=Directory Manager
  password=abcd
  base=dc=example,dc=com
  </code></pre>
  
  <p>My question is, what is exactly this <em>userDn</em> and <em>base</em>? What does these signifies? And which <em>userDn</em> value we need to specify in this configuration??</p>