Acids are solutions that contain hydrogen ions or hydronium ions and have a pH below 7. They taste sour and can corrode metals. Bases are solutions that contain hydroxide ions and have a pH above 7. They taste bitter and feel soapy. The document discusses various properties of acids and bases like their reactions, uses in products and industry, and how pH is measured. It also provides examples of experiments to observe the reactivity of acids and bases with different substances.