AWS long-term archival storage service for data you rarely access. Like putting old documents in a warehouse - cheaper to store but takes time to retrieve.
A company stores old employee records in Glacier for compliance, accessing them only when legally required.
All are low-cost, long-term object storage options designed for rarely accessed data. They trade cheaper storage for slower retrieval times and, in some cases, retrieval fees and minimum storage durations. AWS implements Glacier as S3 storage classes (e.g., S3 Glacier Flexible Retrieval, S3 Glacier Deep Archive) managed through the S3 API.