What are IVs?
IVs stands for "individual values". Once a Pokémon is spawned in, the IVs are determined as fixed numbers at random. Each stat has it's own IV ranging from 1 - 31. You can check a Pokémon's IVs by doing /ivs (slot).
TL;DR - The higher IV the Pokémon has in a slot, the better that stat is.
Why do you breed and how do you do it?
Most people breed to increase the IVs of their Pokémon. Others breed lots of the same Pokémon in an attempt to hatch a shiny Pokémon. To start breeding you first need to decide what Pokémon you are going to breed. Then go onto Bulbapedia and figure out what egg group that specific Pokémon is (alternatively you can do "/wiki (insert Pokémon name) egggroup"). For this occasion, I will be using Popplio as an example.
To start off I will need a ranch block. You craft them like this:
Spoiler: Crafting recipe for ranch block.Show
Next I go onto Bulbapedia and find out what Popplio's egg group(s) are. Pokémon can have 1 or 2 different egg groups.
Spoiler: Popplio's egg group.Show
Popplio is in the Water 1 and Field egg group(s). When I click on "Field" and "Water 1" it's obvious there is more in the Field egg group. So then I look for common Pokémon that are male in the Field egg group in /ah. Try to find a Pokémon in the field egg group with more or exactly 31 ivs in 4 slots. Make sure the Pokémon you want as the offspring is the female parent as that is what the offspring will always be. One exception is when you are breeding with ditto then which it doesn't matter what gender the Pokémon you use is, the Pokémon that isn't ditto will always be the offspring. Once you have
your male Pokémon in the same egg group as your female you'll need to setup a 9x9. Depending on the type of the Pokémon you are breeding, you'll need to fill in the 9x9 with different blocks. Put your ranch block directly in the middle. Here is the list of the blocks you may need:
Popplio is a water/fairy type, and it would be easier getting Sea Lanterns than any of the fairy type breeding environment blocks. Mankey is a fighting type, so I chose Stone Brick as the best block. The higher the value of the block the quicker the Pokémon breeds.
Spoiler: Example of what the 9x9 should look like.Show
Your breeding should be operational and in (depending on the environment) 2h/30m - 37m you should have an egg when you right click the ranch block. You can read more about the times of eggs being produced here.
Spoiler: Useful ItemsShow
Guide made by KyoDaz#6343