In Chemistry, systems are portions of matter marked by specific chemical or physical behavior.

In Ceramics, for example, all watery suspensions involved in the production process (such as grit and glaze suspensions, engobes, smaltobbi, etc.) can be considered systems.

Broadening the perspective, in Science a system is an object of study that, despite being made up of different elements mutually interconnected and interacting with each other and with the external environment, reacts or evolves as a whole, with its own general laws.

Based on their structure, we can identify heterogenous and homogeneous systems. In simple words: a system consisting of several phases (for example, solid and liquid phases) is defined as polyphasic and heterogeneous. Conversely, a single-phase system is defined as homogeneous or monophasic. The type of phase is irrelevant. A heterogeneous system may contain several solid and liquid phases at the same time but only one gaseous phase.