The term "d-block" refers to a specific section of the periodic table that includes transition metals. These elements are characterized by their ability to form variable oxidation states and to create colored compounds. The d-block elements are found in groups 3 to 12 and include metals such as iron, copper, and gold. D-block elements are known for their high melting and boiling points, as well as their conductivity of electricity. They often play important roles in industrial processes and are essential in various applications, including catalysts and electronic devices. Their unique properties make them crucial in both chemistry and materials science.