root和alias的区别

• root和alias的区别

例:
location /images/ {
      root /data/web; #路径，实际路径跟上头
      http://www.aaa.com/images/a.jpg ==> /data/web/images/a.jpg
}
例:
location /images/ {
      alias /data/web;
      http://www.aaa.com/images/a.jpg ==> /data/web/a.jpg
}