Irrigation management in greenhouses plays a critical role in determining yield, crop quality, and water resource efficiency. Given the increasing limitations of water resources and the need to improve production sustainability, it is essential to develop precise irrigation strategies in soilless and soilless cultivation systems. In soil systems, continuous monitoring of substrate moisture, physical properties, and soil water holding capacity is the basis for irrigation regulation. In contrast, soilless cultivation, especially hydroponics, requires precise control of nutrient solution, electrical conductivity (EC), pH, and irrigation frequency at short intervals to maintain water and nutrient balance. Traditional irrigation methods, which rely mainly on fixed timing or limited environmental variables, are often inefficient in responding to the precise and instantaneous needs of the plant. Recent advances in environmental and plant sensors, transpiration monitoring, physiological index analysis, and the use of artificial intelligence algorithms have opened new horizons for smart irrigation management. However, effective application of these technologies requires accurate calibration, localization of models, and adaptation to climatic conditions, crop type, and greenhouse technical infrastructure. The aim of this paper is to review and compare modern and traditional approaches to irrigation management in soil and soilless greenhouse crops. The potential of advanced technologies in optimizing water consumption and increasing production efficiency is also evaluated. The integration of smart systems with continuous monitoring of plant water requirements is introduced as an effective solution for sustainable management of water resources in greenhouses. This paper provides a practical framework for selecting and optimizing irrigation methods based on the type of growing medium, plant water requirements, and available technical facilities, and explains paths to achieving sustainable and efficient production.