An AWS S3 bucket is a scalable cloud storage resource provided by Amazon Web Services (AWS). It allows users to store, organize, and retrieve any amount of data, such as documents, images, or backups, from anywhere on the internet. S3 buckets are commonly used for data archiving, website hosting, backup solutions, and as storage for cloud-native applications. Each bucket has configurable access permissions and security settings, enabling organizations to control who can access or modify the stored data. Misconfigured S3 buckets can lead to data breaches, making proper security management essential.