Try segregating the things around you as pure substances or mixtures.

Some of the things around us are: Tap water, Milk, Naphthalene balls, Sodium chloride, Air, Gold ornaments, Ice-cream, Steel, Distilled water, Diamond, Steam, Kerosene oil, Alum, Salt solution, Brass, Alcohol, Vinegar. Graphite, Wood and Baking soda. We can segregate (or separate) these things as pure substances or mixture of as shown below:

A pure substance is made up of only one kind of particles. All the constituent particles of a pure substance are the same in their chemical nature. These particles may be atoms or molecules. All the elements and compounds are pure substances because they contain only one kind of particles. A pure substance cannot be separated into other kinds of matter by any physical process.

A mixture contains more than one substance, element and/or compound mixed in any proportion. Mixtures can be separated into pure substances using appropriate separation techniques.