WP_HOME is another wp-config.php option added in WordPress Version 2.2. Similar to WP_SITEURL, WP_HOME overrides the wp_options table value for home but does not change it permanently. home is the address you want people to type in their browser to reach your WordPress blog. It should include the http:// part and should not have a slash "/" at the end.
If you won't change the Database value though, so need manually add WP_HOME and WP_SITEURL in wp-config