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Why is division used in botany where zoology uses phylum?

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A diagram showing the hierarchy of animal classification in taxonomy, with colored boxes arranged from broadest to most specific: domain, kingdom, phylum, class, order, family, genus, and species. — taxonomy Animals and other organisms are classified within a succession of nested groups that ranges from the general to the particular.

In biological taxonomy, the terms "division" and "phylum" represent the same level of organizational hierarchy; however, they are used by different scientific disciplines due to historical convention.123

"Phylum" is the standard term used in zoology, while "division" is the traditional term used in botany. Because each major group of organisms has its own unique taxonomic history, these distinct naming conventions have been preserved over time. There are no explicit biological or structural criteria that mandate the use of one term over the other; they are simply equivalent categories that reflect the separate traditions of botanical and zoological classification.12

This dual terminology can create ambiguity when classifying organisms that do not fit neatly into traditional plant or animal categories, such as certain protists. In such cases, scientists typically follow the prevailing usage of the field most interested in the specific organism—applying "phylum" to animal-like protozoa and "division" to more plantlike groups.3