The process or result of sorting things into specific groups or categories based on shared features.
From categorise (British spelling of categorize) plus -tion. Ultimately from Greek kategoria. The British spelling uses 's' while American uses 'z', reflecting different etymological conventions between American and British English.
The human brain is essentially a categorisation machine—we can't perceive or understand the world without instantly sorting it into groups, which is why even babies develop categories before they learn language.
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