A file that maps between transformed code (like minified or transpiled code) and the original source code, enabling developers to debug the original code even when the browser runs the transformed version. It creates a bridge between what you wrote and what actually executes.
Introduced by Google in 2011 as web applications became more complex and required build processes that transformed code. The term 'map' comes from cartography, as these files literally map locations between two different representations of the same content.
Source maps are like GPS coordinates for your code - when an error happens in the minified mess that browsers run, they help you find exactly where the problem is in your beautiful, readable original code! Without them, debugging would be like trying to find a specific house in a city where all the street signs have been replaced with random numbers.
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