You must first understand a solution before understanding colloids and emulsions. Fill a clear drinking glass about halfway with water. Obtain a little bit of water-soluble dye, like Easter egg coloring or food coloring, and place one drop gently on top of the water. Notice that as time elapses, the dye is slowly dissolved in the water. The dye molecules bind tightly with the water molecules, and the color is eventually completely dispersed in the water. You can take photographs of the dissolving process every five minutes to visually demonstrate how a solution is obtained.
Peel the label off a clear plastic bottle with a tight-fitting cap. Soda bottles will work. Fill the bottle about one-quarter full with water. Fill about halfway up with vegetable oil. Place the bottle down and let it sit about 10 minutes. Photograph the bottle. Notice the oil and water separated, with the oil floating on top. This is because oil and water are different liquids. Place the cap on tightly and shake the bottle. Place it down quickly and photograph. Notice that the oil is interspersed with the water but is not dissolved. Let the bottle sit. Notice that the oil eventually floats to the top of the water. The interspersion phase is a colloid.
According to the Education for the Information Age, an emulsion is a specific kind of colloid. The difference is that in a emulsion, the interspersed particles are a lot finer. The particles may even be on the microscopic or molecular level. Think of water molecules as being blue marbles, and oil molecules being red marbles. If you shake the bag of marbles, they will become interspersed. Unlike marbles, however, the oil will eventually settle above the water. To make an emulsion, shake the bottle you made the colloid in even more. Shake it very hard, then give it to another person to shake. Pass the bottle to several people until the oil is thoroughly mixed in with the water. Notice it looks cloudy, since the oil is finely dispersed. Set the bottle down. Eventually, like a colloid, the oil and water will separate, with the oil floating on top of the water.