Binders are materials used to join together other materials.
We can use many types of binders for building:
Plaster: It is made from crushed gypsum. It is used to make archways, partitions and as covering for walls.
Cement: It is a grey powder made from a mixture of limestone, clay and gypsum.
Mortar: It is a mixture made from cement, sand and water. It is used to hold together construction materials like bricks or paving stones.
Concrete: it is a mixture of gravel, sand, cement and water. When it dries it hardens forming a strong material. It is used to make foundations, beams, columns, arches, etc.