The first rule allows cross-origin PUT, POST, and DELETE requests from the https://www.example1.com origin. The rule also allows all headers in a preflight OPTIONS request through the Access-Control-Request-Headers header. In response to any preflight OPTIONS request, Amazon S3 will return any requested headers.
The second rule allows same cross-origin requests as the first rule but the rule applies to another origin, https://www.example2.com.
The third rule allows cross-origin GET requests from all origins. The '*' wildcard character refers to all origins.