Efficient generally refers to performance with the least amount of waste or sometimes the ability to avoid waste. The term efficient is very subjective to context and observations regarding use. Two of the subjective measurements are the consumption of resources and the use of resources to meet a goal. Each are perceptions on the same consideration, one view is from the producer and the other from the customer. Efficient thinking in mind and the brain is similar. The neurobiology of the brain produces thoughts, and the neurocognition of the mind consumes the thoughts.
Waste has some negative connotations, e.g. trash, but a wastebasket is very efficient for collecting trash. In production companies, the consumption of resources manufactures a product. In manufacturing, quality is an efficiency statement that appears to be a perception measurement about resource depilation that occurred to make the finished goods. Customers who purchase the goods make a quality assessment to buy based on their judgment the goods meet the perceived use of their personal resources,
Illumination is the waste of electric power applied to a light bulb. A 10 Watt light bulb is more efficient than 100 Watt light bulb regarding power consumption. However, from a different perspective, the illumination produced by 100 Watt bulb may be more efficient to reduce the darkness. In energy consumption, watts is a measurement of the waste cost associated with the power to produce electricity. Energy company uses waste consumption to make money. The more waste, the more money