The document discusses different types of conductors used in power transmission. It describes the major materials used which include copper, aluminum, and aluminum alloys. The major types of conductors are identified as AAC (All Aluminum Conductor), AAAC (All Aluminum Alloy Conductor), ACSR (Aluminum Conductor Steel Reinforced), and ACAR (Aluminum Conductor Aluminum Alloy Reinforced). Key factors to consider in conductor selection include physical properties of the materials, mechanical characteristics, electrical performance, and cost. The design of conductors involves tradeoffs between these various factors.