As mentioned in the comments (and the documentation), value is an alias to path. Spring often declares the value element as an alias to a commonly used element. In the case of @RequestMapping (and @GetMapping, …) this is the path property:
This is an alias for
path(). For example@RequestMapping("/foo")is equivalent to@RequestMapping(path="/foo").
The reasoning behind this is that the value element is the default when it comes to annotations, so it allows you to write code in a more concise way.
Other examples of this are:
@RequestParam(value→name)@PathVariable(value→name)- …
However, aliases aren’t limited to annotation elements only, because as you demonstrated in your example, @GetMapping is an alias for @RequestMapping(method = RequestMethod.GET).
Just looking for references of AliasFor in their code allows you to see that they do this quite often.