Wood is a block gained by crafting using one Tree Trunk, which will gain 2 blocks.
It can be used well for building, as it's not affected by gravity.
Wood is an important crafting material.
It is essential for creating new Crafting Tables to deal with more material at once.
Also torches are important, as they are one of the few blocks providing light. Those are also crafted with wood.
|Tree Trunk||→||Wood, 2|
|Wood, 3||→||Crafting Table|
|Wood||Iron Block||→||Rail, 4|