A classification of a colloid should include a description of the continuous phase (the phase in which the colloidal particles are dispersed) and the dispersed phase (the particles themselves). The description of the continuous phase should include its physical state (solid, liquid, or gas). The corresponding description of the dispersed phase should likewise include its physical state, shape, size, and dispersion of particle sizes (bubbles, droplets, solid particles), and any possible aggregation. Table 6.1 provides a basic guide to the characterization of different colloidal systems.