This is Part 1 of Applied Discrete Structures, containing the fundamental concepts taught in a one semester course in discrete mathematics. It corresponds with the content of Discrete Structures I at UMass Lowell, which is a required course for students in Computer Science, Mathematics and Information Technology. Part II - Applied Abstract Algebra would normally be used in a second semester course such as Discrete Structures II at UMass Lowell. Applied Discrete Structures has been approved by the American Institute of Mathematics as part of their Open Textbook Initiative. For more information on open textbooks, visit http: //www.aimath.org/textbooks/. This version was created using Mathbook XML (https: //mathbook.pugetsound.edu/)