This document provides a summary of key concepts from a compiled lecture on engineering economy. It defines important cost terminology used in engineering economy like fixed costs, variable costs, incremental costs, recurring costs, non-recurring costs, direct costs, indirect costs, overhead costs, standard costs, cash costs, book costs, opportunity costs, and sunk costs. It also outlines the table of contents and chapters that are covered in the lecture, including cost concepts and design economics, money-time relationships, depreciation, investment evaluation methods, comparing alternatives, and feasibility studies.