This paper provides a comprehensive review of the business schemes associated with Vehicle-to-Grid (V2G) technology, focusing on its feasibility and challenges in the electricity market. Electric vehicles (EVs) are playing a crucial role in the global transition towards decarbonization and renewable energy resources (RERs). However, the increasing popularity of EVs has led to challenges for the power grid, such as intensified peak-to-valley load differentials and transformer overloading. V2G technology, which enables bidirectional charging and discharging, offers a promising solution by leveraging EVs as energy storage devices. The paper explores various business schemes, including peak-to-valley arbitrage, spot market participation, demand response (DR), frequency regulation, voltage regulation, spinning reserve, and black start. It also examines real-world use cases and application scenarios, such as home-based, workplace-based, and commercial site-based V2G. The challenges faced by V2G technology, including technical, economic, and social aspects, are discussed in detail. The paper highlights the need for further research and policy support to address these challenges and promote the development of V2G technology.This paper provides a comprehensive review of the business schemes associated with Vehicle-to-Grid (V2G) technology, focusing on its feasibility and challenges in the electricity market. Electric vehicles (EVs) are playing a crucial role in the global transition towards decarbonization and renewable energy resources (RERs). However, the increasing popularity of EVs has led to challenges for the power grid, such as intensified peak-to-valley load differentials and transformer overloading. V2G technology, which enables bidirectional charging and discharging, offers a promising solution by leveraging EVs as energy storage devices. The paper explores various business schemes, including peak-to-valley arbitrage, spot market participation, demand response (DR), frequency regulation, voltage regulation, spinning reserve, and black start. It also examines real-world use cases and application scenarios, such as home-based, workplace-based, and commercial site-based V2G. The challenges faced by V2G technology, including technical, economic, and social aspects, are discussed in detail. The paper highlights the need for further research and policy support to address these challenges and promote the development of V2G technology.