This document discusses different types of engineering materials, including metals and non-metals. It describes how metals can be divided into ferrous and non-ferrous categories, with ferrous metals containing iron like cast iron and steel, the two most important ferrous metals. It also notes that certain elements can be added to steel to improve its properties. The document then explains that plastics and ceramics are examples of non-metals, with plastics categorized as thermoplastics and thermosets, and ceramics used when materials need to withstand high temperatures.