apache多站点配置中ServerName ServerAlias什么意思?

<VirtualHost *:80>    #ServerAdmin 邮箱    ServerName *.vpigirl.com    ServerAlias *.vpigirl.com *.vampire.com    ErrorLog "logs/vpigirl.com-error.log"    CustomLog "logs/vpigirl.com-access.log" common    RewriteEngine on    RewriteMap lowercase int:tolower    RewriteMap vhost txt:C:/website/Apache22/vhost.map    RewriteCond ${lowercase:%{SERVER_NAME}} ^(.+)$    RewriteCond ${vhost:%1} ^(C:/.*)$    RewriteRule ^/(.*)$ %1/$1</VirtualHost>

ServerName 是服务的名字，只能有一个值。（可以写多个，但是好似没有效果）
ServerAlias 就是给 ServerName 起别名，用它也可以访问到服务器，可以定义多个，用空格隔开即可。