Short for extension, typically referring to a file extension or telephone extension.
Abbreviation of 'extension,' from Latin 'extensio' meaning a stretching out, from 'extendere.' The computing sense developed as files needed additional identifiers beyond their names to indicate format or type.
File extensions like '.txt' or '.pdf' represent one of computing's most elegant solutions—a simple suffix that tells both humans and machines what to expect inside a file. This system, now so fundamental we barely notice it, revolutionized how computers organize and process information by making file types instantly recognizable.
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