Are you ready to learn?
Cause I am about to lay it on you. By it I mean info.
Firstly IVs are pretty much pokemon genetics.
When you catch a pokemon its IVs are randomly generated and each stat is given a number between 1 and 31 with 31 being the best.
When breeding pokemon, under normal circumstances, the child will inherit 3 stats at random from it's parents. 3 will be generated randomly. However, there are some items that help with IV breeding. The first are the power items which are dual purpose and are also used for EV training. Let's have a senario:
You have a ditto with perfect HP and Def. You are breeding it with a torchic with no perfect stats.
If you give the ditto the Power Weight and breed, every offspring will have perfect HP and have a chance to have perfect def.
When you IV breed you continually switch out lesser pokemon for better ones. I.e. taking out the torchic with no perfect IVs and putting in one with two.
When you achieve a torchic with three perfect IVs, it is time to unleash the second of the useful breeding items, the destiny knot. This item allows 5IVs to be passed down from the parents. This means that it is now feasible to get pokemon with 5 perfect IVs without RNG Abuse(something that is beyond even me.)
When you breed, just keep on switching until you get a 3, put on the destiny knot and keep going until 5.
EVs are points that are obtained whenever a pokemon gains exp.
All pokemon will give 1 or 2 EVs. However, using the aforementioned power items you can get a huge boost while training. Another useful tool to get is pokerus which I won't get into because Bulbapedia explains it well.
Before Gen VI and after gen 2, pokemon could have up to 255 evs in a stat and 510 total. In gen VI this was changed to 252 max in a stat.
If you have any questions PM me.
Sources:
http://bulbapedia.bulbagarden.net/wiki/IVs
http://bulbapedia.bulbagarden.net/wiki/EVs
http://bulbapedia.bulbagarden.net/wiki/EV-enhancing_item
http://www.gamefaqs.com/boards/696959-pokemon-x/67535721
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