Chapter 10: Treasure and Magical Items
One of the shorter chapters in the book. In the PHB, this is a very very brief overview of treasure types and a 1 page discussion on how to Divide and store treasure. As such, this chapter is very rarely read by players and DMs alike. If you have a copy of the 2nd edition PHB, I strongly urge you to read/re-read the Dividing and Storing Treasure section if nothing else as there are many opportunities for RP situations mentioned, some of which the average player or DM often forgets or never thinks of in the first place.
The DMG chapter can be broken down into three sections. The first forces DMs to think about what forms treasure takes, why it exists, who has it, and where it exists. There's bits of advice such as making sure random encounter treasures are smaller than planned encounter treasures and how to deal with treasure imbalance(pauper and monty haul campaigns).
The second section discusses magical items. It includes advice such as unintelligent monsters as random encounters should not, under normal circumstances, be carrying magic items, while intelligent creatures will actually tend to use them. It also advises AGAINST allowing magical item shops, or allowing players to sell magic items.
The second part of this section discusses the creation, destruction, and recharging of magic items. As a reminder, A wizard may make scrolls and potions at 9th level and other magic items at 11th level. Likewise, a priest character can make scrolls at 7th level, a handful of potions at 9th level, and other items at 11th level. Beyond this, the DM has to decide what form research will take for the caster to learn how to make any given item. These are all fairly standard, and most groups that actually bother with Magic Item creation already use the rules as presented(though some groups choose to ignore the Enchant an Item and Permanency spell rules as a part of item creation).
The last section in the chapter is about Artifacts and Relics. Interestingly, the entire section is an optional rule, and thus not actually a part of "Core rules" as is being discussed in this article series. Overall, I don't think the game really loses much by not including them, but I know many DMs and players who would disagree.