Final answer:
Amazon S3 provides instant read-after-write consistency for new objects uploaded via PUT requests but offers eventual consistency for updates to existing objects.
Step-by-step explanation:
Amazon S3, or Simple Storage Service, offers read-after-write consistency for HTTP PUT requests of new objects. This means that once a file is uploaded using a PUT operation, it can be immediately read. However, updates to existing objects or PUTS that overwrite existing objects are eventually consistent. This means that if a PUT request is made to update an existing object, it might take some time for all the GET requests to reflect the new object version due to distributed nature of S3. For a short while, some GET requests might still retrieve the old version.
For example, if you were to upload a new image to S3 and then immediately attempt to access it, you should be able to retrieve the image without any issues. In contrast, if you update an existing file, then there may be a brief delay before the new version of the file is available for retrieval.