php的LDAP中$ldapBaseDn和$ldapBindDn的区别？

Question

<?php  
namespace Common\Model;  
  
class LdapModel {  
    private $ldapHost; // LDAP服务器地址  
    private $ldapPort; // LDAP服务器端口  
    private $ldapBaseDn; // 基础DN  
    private $ldapBindDn; // 绑定DN  
    private $ldapBindPassword; // 绑定密码  
    private $ldapConn; // LDAP连接资源  
  
    public function __construct($host, $port, $baseDn, $bindDn, $bindPassword) {  
        $this->ldapHost = $host;  
        $this->ldapPort = $port;  
        $this->ldapBaseDn = $baseDn;  
        $this->ldapBindDn = $bindDn;  
        $this->ldapBindPassword = $bindPassword;  
        $this->connect();  
    }  
  
    private function connect() {  
        $this->ldapConn = ldap_connect($this->ldapHost, $this->ldapPort);  
        if (!$this->ldapConn) {  
            throw new Exception("无法连接到LDAP服务器");  
        }  
  
        if (!ldap_bind($this->ldapConn, $this->ldapBindDn, $this->ldapBindPassword)) {  
            throw new Exception("LDAP绑定失败");  
        }  
    }  
  
    public function search($filter, $attributes = array()) {  
        $sr = ldap_search($this->ldapConn, $this->ldapBaseDn, $filter, $attributes);  
        $entries = ldap_get_entries($this->ldapConn, $sr);  
        return $entries;  
    }  
  
    // 你可以根据需要添加更多的LDAP操作方法，比如添加、修改、删除用户等。  
}