In this chapter, Joshua assigns the territorial inheritance to Manasseh.
This is a much longer chapter than the previous one, but of course my readers should remember that the chapter segmentation was done many centuries after the bible was initially written, so the content of chapters 16 and 17 should be thought of as a continuous thought. This is especially so because the header statement in Joshua 16 references the inheritance given to the sons of Joseph (Josh 16:1).
This chapter describes the territory of Manasseh, and the first thing to remember is that Manasseh was the only tribe which is given land both east and west of the Jordan. Manasseh is also the tribe where some of the women (only daughters with no brothers) are given an inheritance amongst their tribe (cf. Num 27, 36).
In the Transjordan region, Manasseh held the furthest northern territory, above Gad and Reuben, into the Golan Heights. West of the Jordan, Manasseh's territory is contiguous with Ephraim and with the eastern territory. Manasseh is not the furthest northern tribe west of the Jordan, as this chapter tells us that Asher lies on the northern border of Manasseh (v. 10). However, Manasseh is the largest tribe by geographic area.
As with every other tribe so far, we are told that Manasseh was not able to displace all of the nations in their territory (v. 13).
This chapter also contains an interesting short story about the "sons of Joseph" asking for more land, where Joshua essentially replies, "if you are large tribes then you can go earn your land by fighting for it." This story establishes, yet again, the significance of chariots in battle, a point that I belabored when discussing Joshua 11. So that's the first thing I noticed. The second think I noticed is the interesting dynamic between the hill country and the valley land. Most of the land Israel has conquered so far has been hill country, such as the "hill country of Ephraim". The phrase "hill country" appears many times in Joshua 11 and 12 when describing the territory that Israel was fighting in.
The hill country vs. the valley lands is a dichotomy that shares many of the same properties as "pastoral" vs. "agrarian". Hill country is usually fit for low density, nomadic farming. Hillsides are harder to farm on, it can be harder to farm at higher altitude, and water is less reliable at higher altitudes. Rivers and streams almost always flow down from hilltops, gathering more water as they get lower. For all of these reasons, it is possible to raise animals in this environment because they can just graze, and if conditions ever get bad they can leave. Farming requires consistency and stability, which is exactly what rivers provide.
We can imagine, then, the valley lands having many more people, larger cities, and the "iron chariots" that the sons of Joseph are now complaining about. Valley land is better land, and that's precisely why it is going to be harder to capture; the Canaanites will be more thickly packed there. Being given the valley land is highly preferable - if they can obtain it. So far Israel has had a lot of success in their invasion; we will see if this success continues in the generations after Joshua.
Note that the "sons of Joseph" are given their inheritance second after Judah. In future times, these two groups will dominate Israelite politics. Judah will form a kingdom in the south, and Ephraim (the stronger of the two Josephite tribes) will form a kingdom in the north. Assigning these two groups their inheritances first foreshadows that future development.