The number of horizons in a soil profile can vary greatly depending on the soil's formation and location. However, there are typically five main horizons that are commonly recognized:

1. O horizon (Organic Horizon): This is the uppermost layer, composed of decomposing plant and animal matter.

2. A horizon (Topsoil): This layer is rich in organic matter, minerals, and living organisms. It's typically darker than the layers below.

3. E horizon (Eluviated Horizon): This layer is often light in color due to the leaching of minerals and organic matter. It's found beneath the A horizon in some soils.

4. B horizon (Subsoil): This layer accumulates minerals that have been leached from the layers above. It can be denser and harder than the A horizon.

5. C horizon (Parent Material): This is the layer from which the soil is formed. It's typically composed of weathered rock fragments.

Not all soils have all five horizons. Some soils might only have two or three horizons, while others might have more. The specific number and characteristics of horizons can vary widely based on factors like climate, vegetation, and geological history.

It's important to note that there are also sub-horizons within each main horizon, denoted by lowercase letters (e.g., A1, B2, etc.). These sub-horizons represent variations in properties within the main horizon.