Minecraft 1.9 is nicknamed the 'Combat Update', but brings lots of new content that doesn't involve combat. This is a guide to all major features and changes found in the latest 1.9 snapshot.It may not always be up-to-date, so if I left something major out, please let me know. This guide will be updated as new snapshots are released or as I become aware of new important features.Combat ChangesWith 1.9 centering around combat changes, I could write an entire post on this, but I'll keep to the basics for now. The biggest change is that weapons now have a cooldown. In order to deal full damage, you'll have to wait for your weapon to fully ready. It's possible to swing without waiting for the cooldown, but the damage dealt will be minimal.Item damage dealt is also changed. Axes now do the most damage of any tool or weapon. However, they have the longest cooldown time. A table of cooldown times (attack speed) and damage can be found below.Duel WieldingAs part of the combat update, items can now be used in the player's offhand. By pressing a hotkey (default 'f') an item will move into a new slot just to the right of the toolbar. This can be used for blocks, torches, shields, and other items. Right clicking will activate the item in the offhand. Tools and weapons, however, can be wielded in the offhand, but cannot be used.Players are now also able to choose a main hand from the skin customization menu.A Major Armor NerfArmor now gives less protection the more damaged it is. A nearly broken set of armor might provide two armor bars of protection instead of the usual ten. This makes having fully repaired gear imperative to survival.Ender Dragon Fight UpdateThe Ender Dragon fight is now identical to the console and pocket edition fights. The end pillars are spawned in a circle instead of being random. The dragon now has two special attacks. A breath attack, which can be used to obtain Dragon's Breath, leaves an area of effect attack around the player. The dragon will also launch fireballs from above the player.The dragon can be re-summoned by creating a creeper face out of clay blocks.New End GenerationThe End has undergone some major upgrades. After the dragon is defeated, a portal will spawn, which allows the player to access new areas of the end. An enderpearl is the only way to enter the portal.Once through the portal, the player will be met with an unexpected sight: tall, plant-like structures, Chorus plants, End cities, and a variety of smaller islands. The Chorus can be harvested for their fruit and for making purpur blocks. Exploring the end cities is worth it. There, new items, such as Mending and Frost Walking enchantments, can be found. The End ships house one pair of Elytra and a dragon head at the bow.Be careful, though. These structures are littered with Shulkers, new block-like mobs that shoot player-tracking projectiles.The ElytraThe Elytra are a set of wings found in end ships. They allow the player to glide and soar through the world. The Elytra won’t allow the player to fly – not exactly. When equipped in the chestplate armor slot, the wings will automatically deploy after the player falls a few blocks. The Elytra will slow a player’s descent, allowing them a safe landing. For more info on the Elytra, go here.New Arrows and PotionsOne of the first 1.9 features was tipped arrows. These will apply an effect to a mob when hit, and there's an arrow variant for each type of potion. The effects are a lot shorter, though. Currently there's no way to obtain these arrows without cheats or access to the creative inventory. Spectral Arrows are new, and cast an outline on a mob or player when they've been shot. This outline can be seen through walls and from a distance.Brewing Changes & New PotionsA new potion variant, the Lingering Potion, is available through brewing an existing splash potion with Dragon's Breath. Dragon's Breath can be obtained by capturing, well, the dragon's breath when she summons the purple particles from the sky. Clicking those particles with an empty bottle will yield Dragon's Breath.As shown above, all potions now require blaze powder to make. This is consumed slowly, so even a little bit of powder will last a long time. This doesn't just apply to brewing lingering potions.Updated BoatsBoats now come in six types, one for each color of wood, and need oars (which are just wooden shovels). In addition, boats can now carry mobs!Boats are controlled by oars now, and each oar is controlled by a different key. The 'a' key controls the left oar, and the 'd' key controls the right one. The 'w' key, unlike all previous versions, does not have any function. In addition, players can only look 90 degrees in any direction.This section was completely stolen from my blog post.Mending and Frost Walker1.9 adds some new enchantments. These are treasure enchantments, however, meaning they can only be found as loot in special pre-generated chests, such as in End Cities. Frost Walker allows the player to walk on water, which converts the top layer to a modified ice block. This melts shortly after, however, and the ice cannot be obtained.Mending uses experience to repair items automatically. Whenever xp is gained, an item with the Mending enchantment will regain some lost durability. This only applies to equipped and active items (equipped armor and the tool in your hand), so items in the inventory won't be repaired.New CropsA pocket edition feature is coming to the PC version of Minecraft: the beetroot. This crop can be found in villages and the seeds can be found in treasure chests. Eating the plant raw will only restore half a hunger bar, but crafting it into stew will restore three.The Chorus plants that grow in the end can also be planted as a crop, and they'll quickly grow into full-sized chorus plants. This can be done by placing the chorus fruit on a piece of end stone.ShieldsShields are best used in the offhand in addition to a weapon or tool. When right clicking, the shield will activate, deflecting arrows that hit the shield and cancelling a large third of melee damage. A banner can also be combined with a shield, giving a shield a texture other than the default one.Hitting a player with an axe will stun the shield for 5 seconds, during which the shield cannot be used.They're crafted using wooden planks and iron ingots, like so:Updated Mob AIComing soon. I have absolutely no idea what this is (but apparently it's a big deal), so I'm not going to write about it. I hear the Minecraft Wiki is a good resource, though.