Amazon Glacier vs Amazon S3: What are the differences?

Amazon Glacier: Low-cost storage service that provides secure and durable storage for data archiving and backup. In order to keep costs low, Amazon Glacier is optimized for data that is infrequently accessed and for which retrieval times of several hours are suitable. With Amazon Glacier, customers can reliably store large or small amounts of data for as little as $0.01 per gigabyte per month, a significant savings compared to on-premises solutions; Amazon S3: Store and retrieve any amount of data, at any time, from anywhere on the web. Amazon Simple Storage Service provides a fully redundant data storage infrastructure for storing and retrieving any amount of data, at any time, from anywhere on the web.

Amazon Glacier and Amazon S3 are primarily classified as "Data Backup" and "Cloud Storage" tools respectively.

Some of the features offered by Amazon Glacier are:

• Low cost – Amazon Glacier is an extremely low-cost, pay-as-you-go storage service that can cost as little as $0.01 per gigabyte per month.
• You store data in Amazon Glacier as archives. An archive can represent a single file or you may choose to combine several files to be uploaded as a single archive. Retrieving archives from Amazon Glacier requires the initiation of a job. Jobs typically complete in 3 to 5 hours. You organize your archives in vaults.
• Secure – Amazon Glacier supports secure transfer of your data over Secure Sockets Layer (SSL) and automatically stores data encrypted at rest using Advanced Encryption Standard (AES) 256, a secure symmetric-key encryption standard using 256-bit encryption keys.

On the other hand, Amazon S3 provides the following key features:

• Write, read, and delete objects containing from 1 byte to 5 terabytes of data each. The number of objects you can store is unlimited.
• Each object is stored in a bucket and retrieved via a unique, developer-assigned key.
• A bucket can be stored in one of several Regions. You can choose a Region to optimize for latency, minimize costs, or address regulatory requirements. Amazon S3 is currently available in the US Standard, US West (Oregon), US West (Northern California), EU (Ireland), Asia Pacific (Singapore), Asia Pacific (Tokyo), Asia Pacific (Sydney), South America (Sao Paulo), and GovCloud (US) Regions. The US Standard Region automatically routes requests to facilities in Northern Virginia or the Pacific Northwest using network maps.

"Cold Storage" is the primary reason why developers consider Amazon Glacier over the competitors, whereas "Reliable" was stated as the key factor in picking Amazon S3.

According to the StackShare community, Amazon S3 has a broader approval, being mentioned in 3235 company stacks & 1615 developers stacks; compared to Amazon Glacier, which is listed in 24 company stacks and 9 developer stacks.