These are the files you received from wordpress.org.
In the wp-content directory are several files, one of which is the plugins folder which comes with akismet and hello.php included. (Two other plugins, named debug-bar and debug-bar-console, are extra plugins I’ve added just to play with. They are not required.)
The zapform folder is the plugin containing the zapform.php file. It is an ordinary text file with the file name extension telling the server to interpret it as a PHP program.