+A hydrogel is a three-dimensional network of [Polymer](/wiki/polymer) chains, highly absorbent yet insoluble in water. Its ability to hold vast amounts of [Water](/wiki/water) makes it invaluable for various applications, from contact lenses to tissue engineering.
+## See also
+- [Biomaterial](/wiki/biomaterial)
+- [Drug Delivery](/wiki/drug_delivery)
+- [Soft Matter](/wiki/soft_matter)