The Chooser let you choose a device which wasn't connected directly to your Apple. (Don't forget the Apple II.) It began as a LaserWriter interface, though it had been partially developed even earlier as a LAN within Apple's Fremont factory where Macs built Macs. AppleTalk was a breakthrough in that the computer did the work of establishing a connection, rather than depending on a LAN specialist to plan a network, assign addresses to each device, install special drivers, install and terminate a wiring scheme, and maintain and circulate the list of users and devices. The downside of machines discovering each other was background chatter among devices handshaking and mapping the net. The solution was breaking large AppleTalk nets into zones with routers, which isolated the chatter to the local zone. A router like the Apple Internet Router or Nuvotech TurboBridge was intelligent as opposed to a repeater like Farallon's Star Controller or Nuvotech's TurboStar.

Zones were cool. Our office had the Oh! Zone, No Parking Zone, Bone Zone, TerrysOwn Zone, and Accounting Zone (guess which users didn't care to program a router). All the local zones tied to the (back)Bone zone which also had the NetModem, file server, and the new fast LaserWriter. Now you may complain that our zone names weren't intuitive, but everybody knew No Parking was sales, Oh! was engineering, and so forth. Names did change from time to time as somebody came up with a good one.

PCs could AppleTalk using either TandyLink (which Radio Shack never let on was AppleTalk), TOPS, PC-MacLAN, or several less popular implementations, and eventually AppleTalk was included in Windows. AppleTalk's advantage over other systems of the day was easy, cheap wiring, especially using PhoneNets. Ethernet at the time required an inch-thick cable with "vampire taps" clamped to it whose transceivers required separate power supplies, complex termination, etc. at a cost of a few hundred dollars per device.

Disclosure: I was VP Engineering at Nuvotech. We did AppleTalk.