“Canaanite...Amorite...Hittite...Perizzite...Jebusite.” All these tribes except the Perizzites were descendants of Noah’s son Ham via Ham’s son Canaan. Genesis says, “Canaan became the father of Sidon (his firstborn)[thus the Phoenicians], Heth [thus the Hittites], the Jebusite, the Amorite, the Girgashite, the Hivite, the Arkite, the Sinite, the Arvadite, the Zemarite, and the Hamathite” (Gen. 10:15-18).
“on the east and on the west.” This refers to Canaanites who lived in the Promised Land, but some toward the east and some toward the west. The Canaanites are described as being in the plains (cp. Num. 13:29; Josh. 5:1; 17:16), and there are plains to the west, the coastal plains or the Mediterranean Sea, and plains to the east that are in the Jordan Valley area).
The picture being painted here in Joshua 11:1-3 is that this is a large coalition, including armies from north to south, and from east to west. It was a unified front of human forces from the various inhabitants of the Promised Land, coming together to stop the Israelites. But the smaller forces of Israel defeated them because Yahweh was fighting for Israel.
“Perizzite.” A tribe of unknown origin in that by the time of Joshua lived in the hill country of Judah and Ephraim. See commentary on Joshua 9:1.