Obviously you have to trade to get the other...
But no they aren't the same game. Emerald has a different story, as Rayquaza is included in the story, and he isn't just and extra you find in Sky Tower. Rayquaza plays a big part in the storyline as he stops Groudon and Kyogre from kicking the crap out of eachother.
No they are not the same game.
There are many Pokemon you catch that are similar in sapphire and emerald but there are many Pokemon emerald can only get and not sapphire.
ruby, sapphire, emerald, fire red, leaf green
You can't catch it in Pokemon Sapphire, Ruby, Emerald. The only way to obtain it is to buy it in the Game Corner for 9999 slot coins in Pokemon FireRed and LeafGreen and then trade it to your Ruby/Sapphire/Emerald game.
The only way to obtain Aerodactyl in Ruby, Sapphire, or Emerald is to trade it from another game.
Pokemon Emerald,Ruby and Sapphire
Well there are a little bit of difference's with saphire and emerald. but I'm not sure if its the same with ruby.
No emerald is better than Sapphire
There are many Pokemon you catch that are similar in sapphire and emerald but there are many Pokemon emerald can only get and not sapphire.
Sapphire and Ruby were released at the same time, then Emerald was released later.
ruby, sapphire, emerald, fire red, leaf green
Emerald..But they are kinda the same
You can't catch it in Pokemon Sapphire, Ruby, Emerald. The only way to obtain it is to buy it in the Game Corner for 9999 slot coins in Pokemon FireRed and LeafGreen and then trade it to your Ruby/Sapphire/Emerald game.
Most likely, not yet though. Emerald and Sapphire are basically the same game.
emerald ruby and sapphire
Seedot can't be caught in Sapphire. You have to trade it over from a Ruby/Emerald game
Emerald.
You can't get Eevee in Pokemon Emerald/Ruby/Sapphire, you have to trade it from another game.