Wood is a regenerative resource as players can grow (3 kinds of) trees from Saplings (currently, as of R27 in January 2016).
Wood is flammable, so caution is adviced when putting torches onto or especially right under blocks of Wood (or Leaves), especially in hot environments like Savannahs, Shores or Jungles. In hot Biomes fire can spread quickly onto other flammable materials and such a whole forest and/or a wooden house can burn down completely to nothingness.
Fires cannot be stopped (currently, as of R27 in January 2016) except by creating aisles/swathes wide enough to prevent flames from spreading over. Also some wooden furniture and many building-blocks crafted from wood and/or leaves are flammable.
Any kind of Wood or Log can be used as Fuel for the Forge, but 2 blocks of Wood will be needed for each process (of melting or hardening), and will burn rather slowly. Some kinds of Wood can be corrupted and such turned into Fuel that burns faster, but needs Lumite Mining Cells to be picked up.
Mind that some crafting recipes will accept many different types of Wood blocks alternatively that you can scroll by clicking on their icons that feature two small golden arrows below in your Crafting Menu (default key "Q") or at Crafting Table (that still exist in old worlds).
Any kind of Wood or Log can be used to craft (as of R27 in January 2016):
- Wood Mining Cell: 4 blocks of any Wood or Log, 1x Vines, and 1 Mushroom (Red Mushroom, Brown Mushroom or Glowing Mushroom)
- Processor: 8 blocks of any kind of Wood or Log, 8 blocks of Stone, 2x Vines
- Moss Torches: 1 block of any kind of Wood or Log, 1 Moss
Currently (as of R27 in January 2016) there are still only 3 kinds of Saplings to grow trees from: Ashenwood, Cragwood, Elderwood. However you can find 9 different kinds of Wood (trees even) in any new Creativerse-world - plus 4 kinds of Logs.
- chestnut-brown Cragwood from trees with dark green leaves and Yellow Flowers in Forests, Woodlands and Grassland biomes. Can be found in all sizes from tiny bush-like to very tall and large (trunks of 8x8 blocks). Cragwood-trees can be grown by players from Cragwood Saplings. On tall Cragwood trees patches of Vines may grow. By harvesting those you will often receive 1 block of Cragwood as well as 1 Vine.
- white Ashenwood from a birch-like tree with Red Flowers that can likewise be found in Forests, Woodlands and Grassland biomes, as well as in valleys of Mountain biomes. Can be found in bush-like sizes, slender medium-size or in a thicker (trunks of 4x4 blocks) version at it's largest. They too can be grown by players from Ashenwood Saplings. Ashenwood-trees very often have Moss growing on their stems. By harvesting these you will often receive 1 block of Ashenwood plus 1 Moss.
- Elderwood from a pinetree-like tree with very dark green leaves and Blue Flowers in Mountains, Tundra and (sometimes snowy) Taiga biomes. In cold areas Elderwood-trees might be snow-covered and/or even have whitened Snowy leaves. Elderwood-trees can also be grown by players from Elderwood Saplings. On old worlds created before R14 Elderwood-trees could also grow into gigantic sequoia-like foliage-trees.
- Shorewood from palm-like trees on beaches or in oasis' in Ocean biomes with big bright green leaves and no blossoms. Shorewood is currently the only kind of wood where Queen Bees cannot be placed on. The rare Shorewood Husk is not some kind of wood though, even if it looks like that; currently it can only be used as Fuel for your Forge - but who knows, it may become more useful in future patches...
- Autumnwood from large trees in the Forest biome with either red Cinnamon Autumnwood Leaves or yellow-brown Citrus Autumnwood leaves or brown Mocha Autumnwood leaves, all of them can contain beige-white starshaped Autumnwood Flowers, and also perhaps Beeswax.
- Weepwood from large trees looking like weeping willows in Swamp biomes with emerald colored leaves and small yellow-green Weepwood Flowers. Weepwood is covered in a lot of Moss too.
- Wildwood from large trees in Jungle biomes with two different kinds of dark green leaves and also two kinds of pink and orange Wildwood Flowers in large amounts that brightly glow golden in the dark. Wildwood also has a lot of Vines growing on it; way more than Cragwood.
- Parchwood from medium-sized trees with "flat" tree-tops in Savannah biomes - with golden leaves but no blossoms.
- Corrupted Wood can be found on the Corruption layer underground which is (currently) the deepest layer of any Creativerse-world. Corrupted Wood grows in the shape of long branches and/or roots spreading all over the "cave"-ceiling as well as over the ground of the Corruption layer, and in 1-block-wide stems in between; sometimes sprouting into small to medium sized trees with bright purple leaves (without any blossoms nor beehives) growing from the branches/roots, also from under Corrupted Water or even hanging upside down from the ceiling.
- Corrupted Trees might originally have been Cragwood, because if purified they turn into Cragwood. Or maybe not, because if you corrupt Ashenwood for example (by using Corrupt Bombs or Corrupted Wood), it will turn into Corrupted Ashenwood and Elderwood will turn into Corrupted Elderwood. However all other kinds of Wood - Cragwood, Shorewood, Autumnwood, Weepwood, Wildwood, Parchwood - will all be corrupted to simple Corrupted Wood, which will then ALL turn into Cragwood when being purified again...
- Cragwood Logs can be found lying on green grass in Forest biomes, but also in the Jungle, in the Taiga and in the water of lakes or rivers on the ground made of Mud.
- Driftwood is a common log lying on sandy beaches close to the Ocean and also on the Ocean floor underwater.
- Weepwood Logs and Mossy Weepwood Logs can be found on green Grass or in Bog Water in Swamp biomes. When harvesting Mossy Weepwood Log, they will often turn into 1 block of Weepwood Log and 1 block of Moss each.