In Pokemon GO there are 3 teams: Team Mystic, Team Valor and Team Instinct.
After reaching Trainer Level 5, you can interact with a Pokemon Gym to choose a team. Professor Willow will introduce you to his three assistants, each leading one of the three teams where you can choose from.
Teams
Team Instinct
Team Instinct is led by Spark, who believes you will never lose when you trust your instincts. Spark studies Pokemon’s intuition, and thinks that it’s related to how Pokemon are hatched.
“Hey! The name’s Spark-the leader of Team Instinct. Pokémon are creatures with excellent intuition. I bet the secret to their intuition is related to how they’re hatched. Come on and join my team! You never lose when you trust your instincts!”
The Yellow Team’s logo is styled after the legendary bird Zapdos.
Team Mystic
The leader of Team Mystic, Blanche, studies Pokemon evolution and claims they cannot lose with their utilization of calm analysis.
“I am Blanche, leader of Team Mystic. The wisdom of Pokémon is immeasurably deep. I am researching why it is that they evolve. My team? With our calm analysis of every situation, we can’t lose!”
The Blue Team’s logo is styled after the legendary bird Articuno.
Team Valor
Team Valor is lead by the Candela, who values training and strength. Candela is researching ways to enhance Pokemon’s natural power as she tries to find true strength.
“I am Candela-Team Valor’s leader! Pokémon are stronger than humans, and they’re warmhearted, too! I’m researching ways to enhance Pokémon’s natural power in the pursuit of true strength.
There’s no doubt that the Pokémon our team trained are the strongest in battle! Are you ready?”
The Red Team’s logo is styled after the legendary bird Moltres.
In-Game Effects
Currently the only game effect of teams is who you are allowed to side with when it comes to atacking or training (defending) Gyms.