The "Microsoft Excel 2019 Step by Step" practice files by Curtis Frye focus on teaching desktop applications and spreadsheets, specifically using Microsoft Excel 2019. Published by Pearson Education, this textbook offers a comprehensive guide to mastering Excel with 480 pages of content. The book covers essential topics and concepts in an easy-to-follow step-by-step manner, making it an ideal resource for learners looking to enhance their skills in desktop applications and spreadsheet management.