This deck is a combo RUG with Animar, Soul of Elements as the commander.
The goal of this destroyer deck is to reduce the generic mana cost of useful/big creatures !
You can do it with bouncing, proliferate, add +1/+1 counters cards or just casting creatures with lower costs. This is a "multi-tool" deck. I know that there is a lot of version for this deck, but I think this one is updated (more recents extensions) and it's not really expensive for a competitive deck (about 500$ max - foils out).
The Wincons are legions : infinite +1/+1 (unblockable Animar/trample), infinite bounce, infinite draw, infinite mana, infinite ETB, infinite tokens and all others stuffs.... This is just the real meaning of "INFINITY" for me.
The real difficulty of Animar's decks depend about how you interact with wraths or blue and red spells. After that, you're safe and you can enjoy... or just destroy your opponents.
Sideboard is just to know what cards could be adding, or because I've not the budget for those (maybe later...).
This is one of the most famous combo deck in MTG (and the best in RUG in my opinion), because it answers to all problems. It's a T1 deck for a long time now and competitive. Cards are not expansive for this type of deck, you can have a really good version for a low cost budget version.
Ok, first, try to call the CloudStone Curio, because it's the "guilt" of almost all combo. This artifact is so powerfull, because it says : When you cats a permanent that's is not a artifact, you can comeback another permanent you control in your hand that shares the same CARD TYPE... just incredible bouncer, and that's why the other artifacts that's you can see in the deck are usefull (you can remove all of them in a lot of version, but I like so much Etherium-Horn (only card that can bounce itself withtout Cloudstone malus on artefacts), and the famous Solemn simulacre).
But ok, the opponent can counter all my stuffs... That's why the deck has been thought for a win in other cases : you can combo with Kiki-Jiki, or grow-up your Animar faster, you can also create a double animar with Spark Double (Ulamog T5 ? Kozilek T4 ? Why not ?!!), you can make a lot of recursions moves from your graveyard if a combo was shutdown (Artisan of Kozilek, Den Protector, Eternal Witness...), and you can bounce them in addition, for repeat the ETB.
So you need Animar if you want a win in majority, but you can win just with creatures when you have core cards : Peregrine drake, Kiki-Jiki, Tishana, Purphoros, Momir Vig... All of these cards are always usefull.
You know that "Inifinity" doesn't mean "win" : If you want to finish your opponent you can multi-trig Purphoros, or add a Walking Ballista, why not bouncing a Decimator 1000 times in the same stack (all your creatures have has trample and inifnite +X/+X), Locust God loves Tishana too, you can make a lot of tokens with flying. And you know, 1/2 games I have my whole deck in my hands by the peregrine combo with Tishana or Zegana (in other version)... so, just enjoy, and learn a lot this deck to understand it and find your own combos.
The better advantage in this deck : it's a versatile deck, there is no absolute version, you can changes all cards from new extensions, and you can find a lot of other combo (infinite Extra-turn with perigrine and TimeStream Navigator or Emrakul The Promised End....). Just ENJOY, BOUNCE AND DESTROY !
edit : Sorry for my english, I hope you will understand the main stuffs of my explanations if you're new.