Yeah i'm late fight me Sources credited at bottom This is the full MC Change-log for 1.12, I did this for 1.11 so why not keep doing it :P New Note block Sounds: New instruments for the Note blocks include Flute, Xylophone, Bell, Chime, and Guitar Other sound effects: Casting and reeling a fishing rod Throwing an eye of ender Putting eye of ender in ender portal frames Eye of ender popping back into item form Player drowning Boat Paddles End Portal Spawning Completing an advancement New Title Screen Splashes The true meaning of covfefe Dont feed chocolate to parrots An illusion! What are you hiding? Somethings not quite right... Tutorial Hints Hints as to how to play the game will be shown at the top right of the screen when a new world is started Advancements!! These replaced achievements -They can be changed via JSON file -Gives rewards such as crafting recipes, loot, xp, and functions Open advancements using L key Toolbar Saver In creative, you can now save your 9-slot hotbar Save up to 9 hotbars! Save toolbars using C + #1-9, load them using X + #1-9 Narrator Using Ctrl + B will automatically open a narrator, that reads player chat messages, including their name -It displays message when not available -Will not read commands or command outputs -Wont read /me messages Credits Read the credits by hitting the copyright system Color Palette All Colors for Wool, Clay, Terracotta, Beds, Banners, Glass and more are now more saturated and bright New Commands /execute /advancement /function /recipe /reload New Gameplay Rules announceAdvancements doLimitedCrafting gameLoopFunction maxCommandChainLength ok, now for the fun stuff :D New Blocks! Concrete -Comes in 16 traditional dye colors -Created when dyed concrete powder comes in contact with water Concrete Powder -Comes in 16 traditional dye colors -When it touches water, it becomes concrete -Craftable using 4 sand, 4 gravel, and 1 dye -Gravity affected (like sand / gravel) Glazed Terracotta -Comes in 16 traditional dye colors -Smelt any terracotta of that color to get glazed terracotta -Can be places in NSEW directions -Wont stick to slime blocks if on top or bottom New Items!! Knowledge Book -Green colored book that will unlock and show you crafting recipers -Only obtainable through /give Spawn Eggs -Parrot New Mobs!!! Illusioner -New Illager -Summons Duplicates of itself, yet only the real one can be hurt -Doesnt have a spawn egg, only obtainable through /summon -Gives player Blindness for 20 second, then shoots with bow -Targets players and villagers Parrots -Tamable with seeds -Fly around!! -Follow and crowd eachother -Imitates sounds of mobs -Parrots dance to jukebox music (which is creepy if you play C418 - 11) -Die if they eat cookies - Right click to make sit -Crouch near a tamed parrot to make it sit on your shoulder -Will fly off if you jump -Can fly with player using elytra -Have 6 health -Come in Green, Blue, Cyan, Gray, and Red Bed Changes Beds can now be dyed the traditional 16 colors!!!!!!!!!!!! You can now bounce on beds like slimeblocks Reduce fall damage Beds now display as 3D object while being held Stair Changes Backs of stairs are now considered blocks -Which means iron bars, fences, and cobble walls now connect to backs of stairs Clay Changes Hardened Clay is now renamed Terracotta Magma Block Changes Now burn infinitely like netherrack Painting Changes Now take up largest possible space Wool Changes New Texture (new texture for sheep aswell) Miscellaneous -2 New Cave Sounds -Buttons, levers, torches, redstone torches, and tripwire hooks can now be placed on jack o lanterns -however, redstone and regular torches cant be placed on top of a jack o lantern -Small command block fixes -SO MANY BUG FIXES!! -When walking backwards, the players body no longer slightly turns -Splash "Now Java 6" changed to "Now Java 8" -1.12 requires Java 8 -All text is now translatable -Closing a crafting table with items inside sends them inside your inventory instead of dropping them -Pressing F1 hides toaster messages -Removed achievements -Removed Herobrine And thats all! Enjoy 1.12!! If i missed anything let me know!! Sources: http://minecraft.gamepedia.com/1.12
The Minecraft wiki is kinda confusing about telling us about the update, so thank you for summarizing :D