The concept of soil horizons developed historically because early soil scientists described these layers based on their visual characteristics. The term "horizon" was used to describe a distinctive layer of soil that differed from the layers above and below. The word horizon comes from the Greek word "horizōn," meaning "boundary" or "dividing line." It is used in this context because soil horizons represent boundaries between different soil layers.

As soil science progressed, scientists realized that soil horizons also have functional significance. Each horizon has its characteristics, properties, and role in soil formation and ecosystem functioning. Soil scientists began using the term "horizon" to collectively refer to these layers due to their historical usage and the importance they hold in understanding soil profiles and interpreting soil information.