Amazon Simple Storage Service (S3) is a cloud-based object storage service offered by Amazon Web Services (AWS). An S3 bucket is a container for storing data in S3. It acts as a folder for storing data and is used for storing and retrieving any amount of data, at any time, from anywhere on the web. Buckets are the basic container structure in S3, and you can use them to store and manage objects, which are individual data files. S3 buckets can be used to store a wide range of data, including text and binary data, images, audio and video files, backups, and archives. They are highly scalable, durable, and secure, making them an ideal solution for storing and accessing data in the cloud.