A brief list of terms you are likely to encounter when you learn about DfE.

Raw materials: All stock used for parts that are fabricated in-house. Examples: 6064 Aluminum, 303 Stainless Steel, Delrin, Redwood. Raw materials can have high environmental impact if excessive resources were used to extract the precursor material from the earth (e.g. a strip mining process), or if a precious resource was harvested (e.g. exotic woods), or if hazardous waste is generated in the creation of the material (e.g. ????), or if high energy is used to create the material (e.g. a steel mill), or if considerable solid or liquid residue is required during manufacture (e.g. paper)
Purchased components: All parts purchased from a supplier that will be assembled into your product with little or no post-processing. Examples: motor, bolt, sensor, cable, belt, data acquisition card.

Consumables: Parts that must be replaced on a regular basis when your product is used. Examples: coffee filters, batteries, film, toner cartridges.

Hazardous materials: Don't want these at all!

Packaging: The wrapping, box, cushioning, store display and so forth used to ship and present the product. When thinking about the environmental impact of packaging, consider the type and amount of packaging material and what happens to the packaging once the customer receives the product. Example: consider the paper and plastic waste used for every latte you buy, or consider the impact of bleached (white) versus unbleached (brown) packaging boxes.

Energy efficiency: Many products require energy for use. This includes all products that plug into the wall, that use batteries, or that use fuel. Energy efficiency can mean that the product is not used for very long (e.g. a hair dryer that dries your hair quickly) or that the product uses very little energy when running (e.g. a refrigerator that uses a high-efficiency electric motor or an automobile with high mpg or a laptop that runs a long time on a single battery charge).

Waste and recycling streams: Most products must be separated into material categories for recycling. For example, the glass jars you recycle at home must have their lids removed, and automobiles destined for the shredder must have their battery removed and oil drained.

Green regulations: Any city, county, state, federal, or international regulations that apply to the product as a whole or to any material or component in the product. For example, University of Minnesota regulations prevent you from throwing batteries away. The state of California has outlawed the use of lead in house keys. The EPA prevents you from dumping manufacturing wastes into streams. Europe has very strict take-back regulations.