What is the difference between a colloid and a suspended liquid?

A suspension is a mixture between two substances, one of which is finely divided and dispersed in the other. Common suspensions include sand in water, dust in air, and droplets of oil in air. 

 

The particles in a colloid can be solid, liquid or bubbles of gas. The medium that they are suspended in can be a solid, liquid or gas (although gas colloids cannot be suspended in gas).