## 2 The Evolution from Cloud Computing to MEC
### Edge Computing  
Edge computing is a newer approach to handling computer tasks, concentrating on performing computations right where the information is produced, i.e., at the edge of the network. It follows a distributed architecture, processing user data as close to their source as possible. Recent data indicate that edge computing is revolutionizing the way information is dealt with. Rather than sending raw data to a central data center for processing and analysis, edge computing tackles this right where the data originate, be it from an online store, a manufacturing unit, a utility, or a smart city. In this setup, tasks such as initial data analysis and checking for potential issues in critical equipment or software are carried out, with the results then sent to the data center for a more thorough examination.  
Edge, fog, and cloud computing share some common traits. All three are connected to distributed computing, but they differ in the physical positioning of computing and storage resources with respect to where data originate. The primary contrast among these technologies lies in determining the ideal location for the necessary resources. Lately, there has been a notable shift in computing, introducing a progressive extension of cloud capabilities to the network edge [44; 45]. This involves harnessing the substantial amount of underutilized computing power and storage resources scattered at the edges of the network, enabling the efficient execution of computation-intensive and time-sensitive tasks on mobile devices. This innovative approach is referred to as Multiaccess Edge Computing (MEC) [46]. Moreover, the advent of 5G technology has spurred a significant demand for new cloud services, given the substantial surge in mobile devices. These services encompass mobile cloud games, remote control services for air and ground vehicles, and applications managing manufacturing processes [7]. To meet these evolving demands within cellular networks, conventional cloud-based platforms are undergoing a transformation, expanding their services to enhance the user Quality of Experience (QoE). This involves providing rapid and robust computing, energy efficiency, ample storage capacity, as well as support for mobility, location awareness, and context awareness [47]. MEC emerges as a solution to address these requirements by seamlessly integrating cloud functionalities at the edge of the network.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Features** & **Cloud Computing** & **Fog Computing** \\ \hline Server hardware & Large-scale data centers (including a significant number of highly capable servers) & Small-scale data centers (moderate or low resources) \\ \hline Server location & Far from end users, installed in large premises, accessed via wired Internet [41] & Located near the end users, communication via Wi-Fi, LTE, 5G, etc. \\ \hline Deployment cost & High, requiring complicated configuration and planning & Low, requires ad hoc deployment with or without planning \\ \hline Computing method & Centralized & Distributed or centralized \\ \hline Operated by & Large companies & Small or large companies \\ \hline System management & Centralized control & Hierarchical control \\ \hline Applications & Cyber-domain, time-tolerant, and high-intensity computation applications & Supports both cyber-domain and cyber-physical applications, specifically latency-sensitive applications \\ \hline Backhaul usage & Frequent use & Lower use, avoiding traffic congestion \\ \hline Latency control & Low & High \\ \hline Reliability & High & Low \\ \hline Maintenance & By technical experts & Requiring little or no human intervention \\ \hline \hline \end{tabular}
\end{table}
Table 2: Differences between Fog and Cloud computing.