Hi!
I found this team on the Internet. can someone explain to me how it works? thanks
Xerneas @ Power Herb
Ability: Fairy Aura
Level: 50
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Moonblast
- Dazzling Gleam
- Geomancy
- Protect
Groudon @ Iron Ball / Life Orb
Ability: Drought
Level: 50
EVs: 156 HP / 252 Atk / 100 SpD
Brave Nature
IVs: 0 Spe
- Precipice Blades
- Rock Slide
- Swords Dance
- Protect
Incineroar @ Safety Goggles
Ability: Intimidate
Level: 50
EVs: 236 HP / 20 Atk / 4 Def / 236 SpD / 12 Spe
Careful Nature
- Flare Blitz
- Fake Out
- Knock Off
- Roar
Bronzong @ Figy Berry
Ability: Heatproof
Level: 50
EVs: 252 HP / 4 Atk / 252 SpD
Sassy Nature
IVs: 0 Spe
- Gyro Ball
- Gravity
- Swagger / Hypnosis
- Trick Room
Tapu Fini @ Mago Berry / Red Card
Ability: Misty Surge
Level: 50
EVs: 252 HP / 212 Def / 44 SpD
Calm Nature
IVs: 0 Atk
- Moonblast
- Heal Pulse
- Swagger / Icy Wind
- Protect
Amoonguss @ Wiki Berry
Ability: Regenerator
Level: 50
EVs: 252 HP / 4 SpA / 252 SpD
Calm Nature
IVs: 0 Atk
- Rage Powder
- Spore
- Clear Smog
- Grass Knot
So it's a team for the current VGC19 format. It seems to have 2 main modes to it, a trick room mode where you're trying to get Groudon in to spam big P Blades, potentially under Gravity, and a faster I guess "take out the steels a win with Xerneas" mode. In terms of items, Iron Ball Groudon seems kind of rogue but it would guarantee you underspeed opposing min speed Groudon/Ogre, as well as a lot of mons in general like Bronzong and Amoonguss, not quite underspeeding Ferrothorn or Stakataka. Goggles on Incineroar prevents rage powders and spores, the former mostly from Amoonguss, but in case you ever play them other users are Jumpluff, Volcarona and Parasect, and the latter from again mostly Amoonguss and some Smeargle (though many are opting for Lovely kiss to get around goggles and to sleep grass types). Redirecting rage powders is nice to prevent your opponent from clicking Rage Powder + Geomancy with their Amoonguss + Xerneas and being confident that any Roars will be redirected away. Red Card Fini is there seemingly as a last ditch effort to get rid of Xerneas after it has set up.
As for EVs, I'm not quite sure what they help do outside of the obvious. Groudon's might be to survive 2 of Ogre's origin pulses in the sun?
252+ SpA Kyogre Origin Pulse vs. 100 HP / 156 SpD Groudon in Sun: 78-92 (41.4 - 48.9%) -- guaranteed 3HKO
Your incineroar lives a +2 Moonblast from Timid Xerneas (I would move those EVs from attack to speed, most Incineroar are running more speed than that and to have a faster Fake out is nice)
+2 252 SpA Fairy Aura Xerneas Moonblast vs. 236 HP / 236+ SpD Incineroar: 169-199 (84.5 - 99.5%) -- guaranteed 2HKO
Fini also has a good chance of living that
+2 252 SpA Fairy Aura Xerneas Moonblast vs. 252 HP / 44+ SpD Tapu Fini: 153-180 (86.4 - 101.6%) -- 12.5% chance to OHKO
Basically it's a sample team for a pretty standard archetype. It's meant for you to use, see what you like, see what you dislike, learn the format, play around with, look at what other people are using and try to see why.