A mixture is broken down into two more groups: homogeneous and heterogeneous.
A homogeneous mixture is a mixture which has uniform composition and properties throughout. For example, air is a homogeneous mixture of gases. Taking a deeper look into homogeneous mixtures is something called a solution. Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. When you look closely, upon mixing salt with water, you can't see the salt particles anymore, making this a homogeneous mixture.
A heterogeneous mixture is simply any mixture that is not uniform in composition. It’s a non-uniform mixture of smaller constituent parts. The parts in the mixture can be separated from one another. Trail mix is an example of this.
Looking further into heterogeneous mixtures are two types of heterogeneous mixtures: suspension and colloid.
A suspension is a heterogeneous mixture that has particles held in a liquid or gas that doesn't settle or isn't dissolved, such as sand in water or oil in water.
Colloids are common in everyday life. A colloid is a substance that appears to be a singular component but is actually made up of two different components. Milk is colloid made up of butter fat and water.