A coordination compound is a complex formed by the combination of a central metal atom or ion and surrounding molecules or ions, known as ligands. These ligands can donate electron pairs to the metal, creating coordinate covalent bonds. Coordination compounds are important in various fields, including chemistry, biology, and materials science. The properties of coordination compounds depend on the nature of the metal and the ligands involved. They can exhibit unique colors, magnetic properties, and reactivity. Common examples include hemoglobin, which carries oxygen in the blood, and copper(II) sulfate, used in agriculture and chemistry.