They all have in common that gathering them lets the user have one wish or more granted, but the sets and conditions vary.
I'll try gathering here the particularities of the various sets, but feel free to help me correct things that are wrong or missing, I can't possibly get it all right on my own!
Original appearance: Dragon Ball manga and Dragon Ball anime.
Location: scattered over planet Earth, regularly gathered and kept at Bulma's place from a certain point in the story.
Number of artefacts: 7.
Size of the artefacts: fits the hand right enough to be grabbed.
Name of the dragon: Shenron / Shenlong
Color of the dragon: green.
Size of the dragon: building-sized.
Power extent:
- Can grant from one to three wishes depending on the dragon’s will (which may vary depending on the "customers" he’s facing, such as usual users or scary users).
Power limitations / constraints:
- Cannot grant a same wish twice.
- Cannot bring a person back to life is that person died of natural causes.
- Cannot properly bring someone back with their body intact if a long time has gone by since their death and the body was mutilated.
- Will directly resurrect a person in the afterlife if that person kept their body there.
- Cannot kill people.
- The ability to act on the bodies of people stronger than him - or God - may or may not work depending on cases (he couldn't turn the androids into humans after the battle against Cell but could turn Goku and his friends into kids after the battle against Majin Boo).
- Once used, the Dragon Balls will scatter around the Earth.
- Once used, the Dragon Balls will become inactive for a whole Earth year (unless some wishes have been left aside or unless an extremely rare Namek power has been used to reactivate them before the year is over).
- If their creator dies or ceases to exist by himself, the Dragon Balls become permanently inactive.
- Seems to have some range limitations when it comes to space (he couldn't locate some Super Dragon Balls because he said the Universe was too big).
Versions / updates:
- Version 1.0 : can only grant one wish no matter what.
- Version 2.0 : can grant more than one wish if he feels that way, usually two, sometimes three. This update happened when Dende took over the role of God before the Cell Game.
- Version 3.0 : can extend a warrior’s powers way beyond its limit (including new, unique forms) even if that warrior is way beyond Shenron’s – or the God of Earth’s – power level. This update happened during the Cell Max crisis.
Original appearance: Dragon Ball manga and Dragon Ball Z anime.
Location: planet Namek, kept by the various village leaders.
Number of artefacts: 7.
Size of the artefacts: larger than a soccer ball.
Name of the dragon: Polunga / Porunga (meaning « God of dreams »).
Color of the dragon: green.
Size of the dragon: building-sized.
Power extent:
- Can grant three wishes in all cases.
- Can bring a person back to life even if that person was already brought back to life in the past.
- Can bring a person back to life and regenerate their body torn to pieces with a single wish of bringing that person to life.
Power limitations / constraints:
- The user is required to speak the Namek language.
- Once used, the Dragon Balls will scatter around Namek.
- Once used, the Dragon Balls will become inactive for a whole Namek year.
- If their creator dies or ceases to exist by himself, the Dragon Balls become permanently inactive.
- Under certain conditions, may not be able to teleport someone if that person refuses.
Versions/updates:
- Version 1.0 : can only bring one person at a time back to life.
- Version 2.0 : can bring whole populations back to life. This update happened after the crisis with Freeza on Namek, which decimated the whole Namek population.
Original appearance: Dragon Ball GT anime.
Location: planet Earth, kept hidden in God's sanctuary.
Number of artefacts: 7.
Size of the artefacts: fits the hand just enough to be grabbed.
Name of the dragon: Shenron / Shenlong (sometimes distinguished as Red Shenron / Red Shenlong in guides).
Color of the dragon: red with yellow or blue eyes.
Size of the dragon: mountain-sized.
Power extent:
- Can act on a person’s body regardless of a person’s power level.
Power limitations / constraints:
- Will scatter the Dragon Balls across space when used and doom the planet to be destroyed in one year if they are not gathered again, making their use extremely dangerous.
Original appearance: Dragon Ball Super manga and Dragon Ball Super anime.
Location: across space, part of them in Universe 6 and part of them in Universe 7.
Number of artefacts: 7.
Size of the artefacts: planet-sized.
Name of the dragon: Super Shenron / Super Shenlong.
Color of the dragon: golden
Size of the dragon: can be bigger than galaxies (requires to go inside to find a lesser-sized copy of itself at its core to enounciate the wishes) but can also appear "city block-sized" when needed, such as in the Tournament of Power.
Power extent:
- Supreme: confirmed to grant any wish.
Power limitations / constraints:
- Gathering the balls requires the ability to travel to another universe and to carry around planet-sized balls.
- Use of the divine language is required, so unless the user is of divine origin themselves, they have to find a deity that agrees with the wish to translate it.
- Will scatter through space in Universes 6 and 7 after a wish has been granted.
- Will become inactive for a year after a wish has been granted.
Original appearance: Super Dragon Ball Heroes (OM1 - OM8).
Location: Scattered throughout time, space and dimensions.
Number of artefacts: 7.
Size of the artefacts: fits the hand right enough to be grabbed.
Name of the dragon: Dark Shenron / Dark Shenlong.
Color of the dragon: Black and a red mane.
Size of the dragon: Seemingly as big as Shenron/Shenlong.
Power extent:
- Can grant one wish, without any known restriction.
- The balls can attach themselves onto a living body, amplifying the individual's power.
- Strong enough to self-defense against powerful warriors, flicking back Future Trunks who tried to interrupt a wish.
Power limitations / constraints:
- Gathering the balls requires being able to travel through space, time and various dimensions.
- Collecting a ball used to amplify a warrior's power requires to be powerful enough to defeat that warrior.
- It is possibly implied that granting a wish can release a vast amount of negative energy, which can have consequences such as creating powerful threatening warriors (Xeno Evil Dragons were created when a wish was granted).
- Can take some time for some wishes, such as refilling someone's energy when there is a great amount to refill.
Original appearance: Dragon Ball Super manga.
Location: planet Cereal.
Number of artefacts: 2.
Size of the artefacts: about the size of a ping pong ball
Name of the dragon: Toronbo
Color of the dragon: icy (bright blue and white)
Size of the dragon: house-sized.
Power extent:
- Can grant wishes going beyond the usual scope of Dragon Balls, though it might require a great sacrifice on behalf of the user if needed.
Power limitations / constraints:
- Has to go as far as sacrificing one’s life expectancy by a great margin to grant certain wishes.
- Seemingly needs a person's permission when asked to teleport them. (asked Bardack before teleporting him, in contrast to Shenron directly teleporting Broly without consent for example).
Original appearance: Dragon Ball Daima anime.
Location: demon realm, one per demon world, kept at the guardian's challenge arena of each world.
Number of artefacts: 3.
Size of the artefacts: larger than a soccer ball.
Name of the dragon: Porunga / Polunga. (shares the same name and appearance as the dragon from Namek, except for the color)
Color of the dragon: magenta. (similar to the Super Saiyan 4's fur or the Super Saiyan God's hair).
Size of the dragon: building-sized. (shares the same name and appearance than the dragon from Namek, except for the color)
Power extent:
- Can grant one wish, without any known restriction.
- Strong enough to defend himself against powerful threats. He managed to effortlessly flick away Gomah's final form (fueled by the Evil Third Eye) that was rushing at him. In comparison, Shenron was killed by a blast from Demon King Piccolo, a foe whose power level has been surpassed by far by a lot of warriors since then.
Power limitations / constraints:
- Reuniting the balls requires defeating three strong opponents (one for each ball).
- Reuniting the balls requires the ability to travel to all three demon worlds (to challenge the guardian of each realm).
- Namek language is required to call forth the dragon and state the wish.