This chapter explores the molecular foundations of heredity and the discovery that life is governed by a discrete, information-bearing code. Beginning with Mendel’s experiments on inheritance, it traces the path from abstract genetic ratios to the identification of DNA as the physical carrier of genetic information. The chapter explains how DNA’s four-letter alphabet encodes biological structure, how its double-helix structure enables accurate replication, and how information flows from DNA to RNA to proteins through transcription and translation. The discrete nature of the genetic code allows for stability, error correction, and long-term evolution, drawing deep parallels with digital information systems. The chapter then examines protein folding as both a biological and computational problem, highlighting why predicting protein structure is difficult in theory yet reliably solved by nature. Recent breakthroughs using machine learning, particularly AlphaFold, illustrate how computational approaches can uncover biological structure without explicit physical simulation. Finally, the chapter turns to gene editing technologies such as CRISPR, showing how biology has become programmable and raising profound questions about the future of medicine, evolution, and human intervention in life’s code.