The increasing demand for food, the lack of natural resources and arable land, and the recent restrictions on energy consumption require an immediate solution in terms of agricultural activities. This paper’s objective was to review hydroponics (a new soilless cultivation technology) and compare it with conventional agriculture (soil cultivation) regarding its environmental impact and water and energy consumption. The soil loss, the crop/soil contamination, and the greenhouse gas emissions were the criteria for the environmental comparison of conventional agriculture and hydroponics. As for resource consumption, the water consumption rates (L/kg), energy consumption rates (kWh), and energy required (kW) were the criteria for comparing conventional agriculture with hydroponics. Tomato and cannabis cultivation were used as case studies in this review. The review results showed that the advantages of hydroponics over conventional cultivation include zero-soil cultivation, land-use efficiency, planting environment cleanliness, fertilizer and resource saving, water consumption reduction, and conservation. The disadvantages of hydroponics versus conventional cultivation were found to include the high investment costs, technical know-how requirements, and higher amount of demanded energy.