The scope and objectives of an IoT project are defined in the planning phase. During this phase, project goals, deliverables, and overall strategy are determined.

ARPANET, the precursor to the modern internet, can be considered a precursor to the Internet of Things (IoT). ARPANET was one of the first wide-area packet-switching networks and laid the foundation for the interconnected networks that led to the development of IoT.

Azure IoT Hub is a service that facilitates bi-directional communication between IoT applications and the devices it manages. Azure Functions, Azure IoT Suite, and Azure Data Factory serve different purposes within the Azure ecosystem.

The concept of IoT can be traced back to the 1970s, even though it became more popular and widely recognized in the 21st century. The first internet-connected device was a Coke machine at Carnegie Mellon University in the early 1980s, but the foundational ideas began earlier.

A static class can have multiple instances, while a singleton class can only have one instance. A static class is a class that is declared as static and can only access static variables and methods. A singleton class is a class that ensures that only one instance of the class exists in the JVM.

The Observer pattern is a design pattern in which an object, called the subject, maintains a list of its dependents and notifies them automatically of any changes to its state. The Observer pattern is used to implement a publish/subscribe mechanism, allowing the subject to be decoupled from its dependents, and allowing multiple dependents to be notified of changes to the subject's state. The Observer pattern is used to implement event-driven systems.

Design Patterns are reusable solutions to common problems that arise in software development. They provide a standardized way of approaching these problems, which can improve the efficiency, maintainability, and understandability of the code.

The Repository and Unit of Work patterns are related, as the Unit of Work is responsible for managing the persistence of data changes, while the Repository provides an abstraction over the data access layer. The Repository can use the Unit of Work to persist changes to the data.

The Facade pattern provides a simplified interface to a complex system, hiding the complexity of the system behind a single interface and making it easier to use

The Façade pattern provides a simplified interface to a complex system, while the Mediator pattern provides a way for components of a system to communicate with each other in a loosely coupled manner. Façade is a one-way communication pattern, while Mediator is a two-way communication pattern.

The Dependency Injection pattern involves passing objects as dependencies to the objects that require them, while the Service Locator pattern involves a central registry that provides objects when requested. The Dependency Injection pattern provides objects to its client as they are needed, while the Service Locator pattern allows objects to request objects they need from a centralized registry.

The Null Object pattern is a behavioral design pattern that provides a default object as a representative of "null" in the context of design patterns.