The Nether is a hell-like dimension, only accessible via a portal.
To create a portal, you need to make a open obsidian square (2 by 3 on the inside) and set it on fire, using flint or steel, or set wood on fire, by use of lava. This dimension, unlike the overworld, has no time of day, leaving the only light sources to be lava, fires, and glowstones. Throughout this dimension, there are a variety of hostile mobs only found. There also are many blocks and resources that can only be found in the nether. Unless using an enchanted shovel, it’s impossible to grow grass or any other plant life, other than those found naturally, in the nether.
Mobs found in the Nether include Zombie Pigmen. These mobs are neutral, but if attacked can spur anger amongst other Zombie Pigmen. The Nether is also home to Ghasts, large flying mobs that have the power to throw fireballs at the player. Blazes can also be found in Nether Fortresses, dropping Blaze Rods.
Nether Fortresses can also be rarely found in the Nether. These large structures are often of an abandoned state and made of Nether Brick blocks. There is also an area above the Nether, which is a void like area that contains a vast open space. The player may build on this area, but no resources may be found.