Spackle can be used to patch small holes and chips in both drywall and plaster walls. By contrast, plaster is applied only to plaster walls. Plaster walls are an alternative to drywall sheets and are most often found in historic buildings.
Spackle dries more quickly than plaster and can be applied to drywall in a single layer. The word "spackle" is often used to describe drywall mud or joint compound as well as true spackle, since the differences among the three products are so slight. However, spackle is available in several different textures, or grains, ranging from light to heavy. Light spackle is used for smaller repairs, while heavy spackle is used for more extensive repairs. Joint compound is available in only one consistency. Spackle also dries more quickly than drywall mud or joint compound. Spackle is more suitable for patching small holes than for joining large sheets of drywall.
Plaster walls are common in historic buildings. In these buildings, small batches of plaster may be applied to fill holes and nicks. It is common to apply two to three coats of plaster when repairing plaster walls. Each layer must dry, or cure, before the next layer can be applied, so repairing walls with plaster can be more time-consuming than repairing walls with spackle.