Path of Exile, League Start Builds. How Do They work?

Character Level 93 Pathfinder Bandit: Alira
Pools 5,993 Life 44 Energy Shield 1,009 Mana
Defences 25,508 Evasion
Resistances 75% Fire 75% Cold 75% Lightning 62% Chaos
Weapon 1 Cold Iron Point Ezomyte Dagger
Weapon 2 Mistwall Lacquered Buckler
Helmet Budget Helmet Lion Pelt
Body Armour Kintsugi Exquisite Leather
Gloves The Embalmer Carnal Mitts
Boots Atziri's Step Slink Boots
Amulet Budget Amulet Agate Amulet
Ring 1 Budget Ring Topaz Ring
Ring 2 Budget Ess Ring Ruby Ring
Belt Budget Belt Leather Belt
Flask 1 Alchemist's Jade Flask of Reflexes
Flask 2 Cautious Eternal Life Flask of Staunching
Flask 3 Coralito's Signature Diamond Flask
Flask 4 Alchemist's Quicksilver Flask of Adrenaline
Flask 5 Alchemist's Quartz Flask of Warding
Jewel Viridian Jewel
Hypnotic Eye Jewel
Weapon 2 Plague Bearer 21/20 Increased Area of Effect 21 Empower 3
Gloves Vaal Blade Vortex 20/20 Poison 20/20 Unleash 20/20 Deadly Ailments 20/20
Helmet Malevolence 20 Summon Skitterbots 20 Enlighten 3 Precision 7
Boots Wither 20 Spell Totem 20 Multiple Totems 20 Faster Casting 20
Weapon 1 Shield Charge 20/20 Faster Attacks 20/20 Fortify 20
Cast when Damage Taken 14 Steelskin 18 Despair 17
Portal 1/20 Vaal Grace 20 Withering Step 20/20