Woods (sometimes called Forests) are a widespread terrain feature in Civilization VI. Woods appear on flat and hilled Grassland, Plains, and Tundra tiles. They do not appear next to Lake tiles unless they are part of a Natural Wonder.
- Yields: +1
Production. - Movement needed: 2 MPs (3 if on Hills)
- Defense provided: +3 (+6 if on Hills)
- Additional traits:
- Can receive a special Tile Improvement, the Lumber Mill.
- +1 Appeal
- +0.5 Faith adjacency bonus to Holy Site districts (rounded down).
There are actually two variants of Woods, which become distinguished after discovering the Conservation civic:
- Old-growth Woods are the ones that already existed in the world (i.e. they have never been removed). After they get included in your territory they gain a bonus +1 Appeal on their own tile (as well as still providing +1 Appeal to all adjacent tiles).
- Second-growth Woods are the ones Builders have planted with their newly-gained Plant Woods ability. They provide the usual +1 Appeal to adjacent tiles (but not their own), and do not provide a Production bonus if Harvested. They are otherwise the same as old-growth Woods.
Strategy
Woods have many uses throughout the game. Forests ensure productivity and protection for civilizations living within them, and provide adjacency bonuses to Holy Sites. Once Machinery (or, in Gathering Storm, Construction) has been researched, Lumber Mills can be built to further increase their 
Production.
Woods can become especially useful in flatlands (regions without Hills) - they are the only Production booster there, barring the odd resource that can be improved with a Mine or Quarry.
In contrast to Rainforests, Woods increase the Appeal of adjacent tiles, making them ideal for Neighborhoods or tourist attractions. The Conservation civic also allows Builders to plant second-growth Woods on any tile where Woods could normally grow - while they don't have as much Appeal as old-growth Woods, they can be used to dress up cities and improve Tundra tiles. Conservation also gives a +1 Appeal on the Woods tile itself for old-growth Woods; this usually is not very useful (because most stuff that depends on Appeal will remove the Woods), except when attempting to designate a National Park. Since the individual Appeal of each and every tile counts in this situation, you may find it possible to use Woods tiles which previously didn't have enough Appeal to be included in the Park. You can even Plant Woods in a vertical diamond-shaped area to gain +2 Appeal for the top and bottom tiles and +3 Appeal for the side tiles - this all but ensures they will have the minimum Appeal needed to designate a National Park.
After researching Mining, Woods can be Harvested to provide a progressive amount of Production (adjusted by game speed, difficulty level, and era) to the city owning the tile. Note that Harvesting second-growth Woods will not yield any Production, so if a city needs the Production more than the Appeal, it's a good idea to Harvest the Woods and then re-plant them after researching Conservation.
Civilopedia entry
The bounty of woods has been crucial in the survival of more than one tribe, providing timber, animals, and plants in such variety as to stagger the imagination. Sadly, civilization has too often chopped them down to make room for farms, roads, and suburbs … and then there are those greedy corporations, looking to grow rich from pelts, logs, and metals.
Gallery
.png "Forest on grassland tile in-game (Civ6).png (880 KB)")
.png "Forest on plains tile in-game (Civ6).png (720 KB)")
.png "Forest on tundra tile in-game (Civ6).png (891 KB)")