In this chapter, the LORD has Joshua designate the six cities of refuge.
The cities of refuge were first mentioned in Num 35, and pretty much everything in this chapter corresponds with what was said there. The only thing that's new about this chapter is that now we are given the names of the six cities (as per Num 35, all of these cities will also be Levitical cities).
I discussed the city of refuge concept extensively in my commentary on Num 35, so I encourage anyone who is interested in learning more to read that.
All I will say about this chapter is that the names of the six cities, like so many other names and places in Joshua, are hard to remember and largely inconsequential. In fact, to my recollection I don't believe there are any stories in the OT where anyone goes to a city of refuge to be protected from an avenger of blood. I don't doubt that this was a significant part of Israel's legal system, but it plays a very small role in the stories of the OT.
As stated in Num 35, there are three cities on each side of the Jordan river. What we learn from this chapter is that the cities are very widely spread out on each side. East of the Jordan, there is one city of refuge in each tribe. West of the Jordan, there is one in the far north (in Naphtali), one in the middle (in Ephraim) and one in the south (Judah). Hebron is still north of the Negev, so the Negev is probably the largest region that doesn't have a city of refuge. This is probably because Judah already has a city of refuge, and the Negev is one of the least populous regions in the country.
Otherwise, this is a really short chapter so there isn't anything more I really need to say here.