Minecraft/The Nether

Flint and Steel
Flint and Steel function as a lighter. It can be made with an Iron Ingot and a piece of Flint. Place them side by side in your crafting grid to get a Flint and Steel. Use it on a flammable material to set it on fire. Flint and Steel is ideal to ignite Nether Portals.

Dimension hopping
To get to the Nether, you will need a Nether Portal. For the Nether Portal, you will need at least 10 blocks of Obsidian.

Build the portal as follows: If you feel so, you can also skip mining Obsidian by collecting the Lava Buckets and one Water Bucket and letting the water flow into the lava like described here. An ideal location is a lava lake, either underground or even on the surface. If you are careful, you can complete the portal with only one bucket. Extra Water Buckets are useful for safety. With that technique you can skip the Diamond Pickaxe and even the Iron Pickaxe, but you should gear up for the dangers in the Nether anyway.

Now you have the frame for the portal. Use the flint and steel on the bottom Obsidian blocks and some purple stuff should now appear inside the frame. When you walk into purple stuff, you will be teleported to the Nether. Beware, the Nether is a dangerous place to go!

The Nether: a parallel world
In Minecraft there are three dimensions: the Overworld, the Nether and The End. The first time you teleport to the Nether, the game will create a Nether dimension completely unique to your Overworld, also based on seed. The game will also create a Nether Portal that is closest to the corresponding place of the portal you used in the Overworld. The Nether is scaled down by a factor of 8. This means that every meter you walk in the Nether corresponds to a distance of eight meters in the Overworld, so if you are far into the game, you can make a fast transport network.

The Nether is filled with fire and is thus very dangerous. There are huge lakes of lava, flying mobs called Ghasts that shoot explosive fireballs at you, magma cubes that multiply on defeat, Zombie Pigmen that can gang up on you if you attack them, Piglins that trade with you if you wear gold armor and attack you if not, and giant aggressive pigs called Hoglins. Endermen and Skeletons also spawn here. Also, water instantly evaporates and thus cannot be placed.

Nether biomes
There are four biomes:
 * Nether wastes are filled with netherrack and fire.
 * Crimson forests have red "trees" and are filled with Piglins and Hoglins.
 * Warped forests are essentially green Crimson forests, but have endermen.
 * Basalt deltas have basalt pillars.