Carving - Technique of cutting and abrading the surface of a block of material to shape it into particular form. Appropriate carving materials in schools include clay, chalk, plaster, soft salt blocks, artificial sandstone, bar soap, and wax.
Modeling - Technique in which a three-dimensional form is manipulated in a soft material such as clay, either modeling clay (Plasticine is a well-known brand) or ceramic clay, or wax.