An efficient search algorithm that finds a target value in a sorted array by repeatedly dividing the search interval in half. It compares the target with the middle element and eliminates half of the remaining elements with each comparison.
'Binary' from Latin 'binarius' meaning 'consisting of two,' referring to the two-way division at each step. 'Search' from Old French 'cerchier.' The algorithm was formalized in the 1940s-50s, though the divide-and-conquer principle is much older.
Binary search is like guessing someone's age between 1 and 100 - you'd start with 50, and if they say 'higher,' you'd guess 75 (halfway between 50 and 100). Each guess eliminates half the possibilities! This is why finding a word in the dictionary is so fast when you flip to the middle first.
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