## 2 Background on Computing Paradigms
### Fog-Related Aspects  
Access gateways or set-top-boxes are end devices that can accommodate Fog computing services. The new paradigm infrastructure permits applications to operate nearby to observe activities easily and handle huge data originating from individuals, processes, or items. The creation of automated feedback is a driving value for the Fog computing concept [30]. Customers benefit from Fog and Cloud services, such as storage, computation, application services, and data provision. In general, it is possible to separate Cloud from Fog, which is closer to clients in terms of proximity, mobile assistance for mobility, and dense location sharing [31], while keeping the Cloud functionality in a distributed and transparent for the user manner. According to NIST, \"Fog computing is a layered model for enabling ubiquitous access to a shared continuum of scalable computing resources. The model facilitates the deployment of distributed, latency-aware applications and services, and consists of fog nodes (physical or virtual), residing between smart end-devices and centralized (cloud) services. The fog nodes are context aware and support common data management and communication system. They can be organized in clusters - either vertically (to support isolation), horizontally (to support federation), or relative to fog nodes' latency-distance to the smart end-devices\" [32]. Generally, Fog computing is considered to be an extension or advancement of Cloud computing, as the latter one ideally focuses mostly on a central system for computing, and it occurs on the upper section of the layers, and Fog is responsible for reducing the load at the Edge layer, particularly at the entrance points and for resource-constrained devices [33]. The use of the term \"Fog Computing\" and \" Edge Computing\" refers to the hosting and performing duties from the network end by Fog devices instead of having a centralized Cloud platform. This means putting certain processes, intelligence, and resources to the Cloud's Edge rather than deriving use and storage in the Cloud. Fog computing is rated as the future huge player when it comes to the Internet of Everything (IoE) [34], and its subgroup of the Internet of Wearable Things (IoWT) [35]. Communication, storage, control, decision-making, and computing close to the Edge of the network are specially chosen by Fog architecture. Here, the executions and data storage are executed to solve the shortcomings of the current infrastructure to access critical missions and use cases, e.g., the data density. OpenFog consortium defines Fog computing as \"a horizontal, system-level architecture that distributes computing, storage, control, and networking functions closer to the users along a Cloud-to-thing continuum\" [36]. Another definition explains Fog as \"an alternative to Cloud computing that puts a substantial amount of storage, communication, control, configuration, measurement, and management at the Edge of a network, rather than establishing channels for the centralized Cloud storage and use, which extends the traditional Cloud computing paradigm to the network Edge\" [37]. The deployment of Fog computing systems is somewhat similar to Edge but dedicated to applications that require higher processing power while still being closer to the user. This explains why devices belonging to the Fog are heterogeneous, raising the question of the ability of Fog computing to overcome the newly created adversaries of managing resources and problem-solving in this heterogeneous setup. Therefore, investigation of related areas such as simulations, resource management, deployment matters, services, and fault tolerance are very simple requirements [38]. As of today, Fog computing architecture lacks standardization, and until recently, there is no definite architecture with given criteria. Despite so, many research articles and journals have managed to develop their versions of Fog computing architecture.