This chapter discusses the fact that technology has been the driving force behind the field of computer forensics. The field of computer forensics evolved into the field of digital forensics as technology continued to influence law enforcement investigations. The chapter shows how almost every criminal investigation now involves some form of digital evidence. It helps the reader to understand the difficulty law enforcement faces when trying to identify and recover evidence from the ever-changing and developing digital world. The chapter explores the importance of evidence integrity and forensic soundness, since digital evidence is only admissible if its authenticity can be verified in a court of law. It overviews the ways in which digital evidence can demonstrate criminal activity of any sort, whether online or offline. The need for computer forensics developed with the onset of the Information Age or Digital Age; this digital revolution was marked by the increased production, transmission, and consumption of, and reliance on, information.