This chapter reviews the historical evolution of various networking and computing technologies that led to Edge computing. This is a foundational chapter for people not familiar with the past trends and progress that led us from large mainframe computers to personal computers (PCs) and now back to large data centers hosting the Cloud while being connected to the Edges of the networks. We present a historic computing spiral, showing that industry has oscillated between large central computers and local computing and hybrid models, leading back to the spiral growth. This requires large central computers to handle the distributed Edge computing demand. We conclude this chapter by visiting the basic concepts of information security, an example of a security attack, and software security requirements for the Cloud.