This book covers topics on Basics of Digital Electronics like Number systems, Basic Logic gates, Combinational Logic circuits-Adders, Subtractors, etc, Sequential Logic Circuits-Flip Flops, Counters, etc, Semiconductor Memories and A/D and D/A converters. This book is useful for Students at Diploma, UG Level and for Competitive Exams Preparations. This book is written in simple language, which is easily understandable by students.