This review discusses hydrogels, their classification, properties, and applications. Hydrogels are polymeric materials with a hydrophilic structure that can absorb large amounts of water. They are widely used in various industrial and environmental applications. Natural hydrogels have been gradually replaced by synthetic ones due to their higher water absorption capacity, longer service life, and availability of raw materials. The review covers the classification of hydrogels based on their source, polymeric composition, configuration, cross-linking type, physical appearance, and electrical charge. It also discusses the preparation methods of hydrogels, including solution polymerization, suspension polymerization, and grafting techniques. The review highlights the importance of hydrogels in various applications such as agriculture, drug delivery, biomedical applications, and environmental protection. The review also discusses the technical features of hydrogels, including their absorption capacity, durability, biodegradability, and pH neutrality. The review emphasizes the need for optimizing the preparation process to achieve the desired properties of hydrogels. The review concludes with an overview of the latest developments in hydrogel technology, including the use of superabsorbent polymers and superporous hydrogels in various applications.This review discusses hydrogels, their classification, properties, and applications. Hydrogels are polymeric materials with a hydrophilic structure that can absorb large amounts of water. They are widely used in various industrial and environmental applications. Natural hydrogels have been gradually replaced by synthetic ones due to their higher water absorption capacity, longer service life, and availability of raw materials. The review covers the classification of hydrogels based on their source, polymeric composition, configuration, cross-linking type, physical appearance, and electrical charge. It also discusses the preparation methods of hydrogels, including solution polymerization, suspension polymerization, and grafting techniques. The review highlights the importance of hydrogels in various applications such as agriculture, drug delivery, biomedical applications, and environmental protection. The review also discusses the technical features of hydrogels, including their absorption capacity, durability, biodegradability, and pH neutrality. The review emphasizes the need for optimizing the preparation process to achieve the desired properties of hydrogels. The review concludes with an overview of the latest developments in hydrogel technology, including the use of superabsorbent polymers and superporous hydrogels in various applications.