What is jQuery Source Map?
As the name suggests, it consists of a whole bunch of information that can be used to map the code within a compressed file back to it's original source . It is used by browser's debugger to help developers debug the minified version of script file. The Chrome and Firefox developer tools both ship with built-in support for source maps. It loaded only when the developer tools are active. Browsers won't load them for application's users.
The map file name is the same as the compressed version , with .map replacing .js. It should be noted that there are two types of source maps . One which is an external file and there is a link to it in the actual file and another one which is embedded in the main file. Browsers actually have to load the entire file for the second type.