What a towed-array sonar requires

Is a towed-array sonar simply a sonar pulled behind the ship on a cable?

Broadly yes, but it also needs a launch and handling system plus control to keep it at the correct depth.

The physical array is indeed towed on a cable behind the ship. That simple description leaves out the equipment needed to deploy, recover, and manage it safely. Operators must also control the array's depth so it samples the intended part of the water column. The exchange turns a familiar silhouette feature into a concise lesson about the machinery behind anti-submarine sensing.