1. Introduction

This chapter delves into the critical role of computing architectures in the modern IT landscape, focusing on the transition from traditional cloud-edge computing to the innovative Between-Cloud-and-Edge Computing. It explores the limitations of current cloud-edge architectures, such as network congestion, latency issues, and privacy concerns, particularly in the context of IoT devices and AI systems. The chapter introduces the concept of Multi-access Edge Computing (MEC) as a solution to these challenges, highlighting its applications in real-time control, data privacy, and security. It also discusses the evolution of MEC, from its initial concept to its current implementation in projects like SoftBank's AI-RAN and the Development Project for a Multi-Node System for MEC. The chapter concludes with an overview of the book's structure, which includes detailed discussions on MEC architectures, hardware, software, design support systems, and applications, providing a comprehensive guide to the future of computing infrastructures.