Why the sqldump export smaller size of database than phpmyadmin

[bruce lee]

I compared the exported .sql file size from using mysqldump export command line with the one that I exported using phpMyadmin default export option, why the former one is smaller? Any idea? If possible, may I know the equivalent cmd line to the default exporting option in phpMyadmin

Here is the very basic cmd line I use

set path=c:\wamp\bin\mysql\mysql5.1.36\bin

mysqldump -u YourUser -p YourDatabaseName > wantedsqlfile.sql