Cement is a binding agent used in construction to create concrete and mortar. It's a fine powder, typically made from limestone, clay, and other materials, that hardens when mixed with water, binding aggregates like sand and gravel. The most common type is Portland cement, which is produced by heating a mixture of limestone and clay. 

• Concrete and Mortar:

  It's a crucial ingredient in concrete (a mixture of cement, water, and aggregates) and mortar (a mixture of cement, sand, and water). 

• Hydration:

  Cement hardens through a chemical reaction called hydration when mixed with water, forming a paste that binds the aggregates. 

• Binding Agent:

  Cement's primary function is to bind together other construction materials like sand, gravel, and crushed rock.