Gaara, you don't know what you're talking about. I assume you don't watch the show so here's a brief summary:
Kami's Dragonballs are the ones seen throughout Dragonball and most of the first 7 DBZ Sagas. They summon Shenron who grants one wish and can ressurect a person once. They are quite small.
Guru's Dragonballs are the ones seen in the Namek, Ginyu and Frieza sagas. They are created and used on Planet Namek, and summon the original dragon, Porunga, who grants 3 wishes and can ressurect people multiple times. They are very large and presumably very heavy.
Dende's Dragonballs are the ones seen after Kami merges with Piccolo, they are created by Dende who is a gifted Namekian boy. He remakes the Dragonballs so they have more power (or harness more of the eternal dragon's power) and summon Shenron, who now grants two wishes. They're smaller than Guru's but a little larger than Kami's (presumably to indicate their greater power.) The size difference is a bit more noticable in the manga.
The Blackstar Dragonballs were created by The Unnamed Namek (Kami before splitting from Piccolo, thus expelling all evil from his body and getting the title of Kami) Because they were created before the split, they have a greater amount of power. They summon an evil representation of Shenron (NOT a Shadowdragon) who grants ANY ONE wish, including killing people and ressurection. They're the same size as Kami's Dragonballs. Once used, they scatter across the universe. Anyway, that's GT and is nothing to do with DBZ, ESF or this thread.