"Science and Engineering Indicators" ("Indicators") is a biennial congressionally mandated report that provides high-quality quantitative information on the U.S. and international science and engineering enterprise. The report employs a variety of presentation styles--such as narrative text, data tables and figures--to make the data accessible to readers with different information needs and different information-processing preferences. The data are "indicators," that is, quantitative summary information on the scope, quality, and vitality of the science and engineering (S&E) enterprise or its change over time. The indicators in this report are intended to contribute to an understanding of the current environment and to inform the development of future policies. "Indicators" includes detailed information about measurement to help readers understand what the reported measures mean, how the data were collected, and how to use the data appropriately. The Methodology Appendix of the report provides detailed information on the methodological, statistical, and data-quality criteria used for the report. The sidebar, "What Makes a Good Indicator?," provides a brief and high-level summary of the data sources used in the report and data-quality issues that influence the interpretation and accuracy of the information presented in "Indicators." "Indicators 2018" includes an overview (Beethika Khan and Carol Robbins) and eight chapters that follow a generally consistent pattern. The chapter titles are as follows: (1) Elementary and Secondary Mathematics and Science Education (Susan L. Rotermund and Peter Muhlberger); (2) Higher Education in Science and Engineering (Jaquelina C. Falkenheim); (3) Science and Engineering Labor Force (Amy Burke); (4) Research and Development: U.S. Trends and International Comparisons (Mark Boroush); (5) Academic Research and Development (Katherine Hale, Karen White, Carol Robbins, Michael Gibbons, and Christina Freyman); (6) Industry, Technology, and the Global Marketplace (Derek Hill); (7) Science and Technology: Public Attitudes and Understanding (John Besley and Peter Muhlberger); and (8) Invention, Knowledge Transfer, and Innovation (Carol Robbins, Mark Boroush, and Derek Hill). In addition, "Indicators 2018" includes an online data tool, State Indicators (Jock Black, Christina Freyman, and Steve Deitz), which provides state-level data on science and technology (S&T); and a digest, comprising a small selection of important indicators from the main report. [Primary responsibility for the production of this volume was assigned to Beethika Khan, Director, Science and Engineering Indicators Program of the National Center for Science and Engineering Statistics (NCSES); John R. Gawalt, Director, NCSES; and the Directorate for Social, Behavioral and Economic Sciences under the leadership of Fay Lomax Cook. For the 2016 report, see ED571833.]