AWS Storage Classes

S3 storage classes are used to assist the concurrent loss of data in one or two facilities.
S3 storage classes maintain the integrity of the data using checksums.
S3 provides lifecycle management for the automatic migration of objects for cost savings.

S3 contains four types of storage classes:

Standard storage class stores the data redundantly across multiple devices in multiple facilities.
It is designed to sustain the loss of 2 facilities concurrently.
Standard is a default storage class if none of the storage class is specified during upload.
It provides low latency and high throughput performance.
It designed for 99.99% availability and 99.999999999% durability

IA stands for infrequently accessed.
Standard IA storage class is used when data is accessed less frequently but requires rapid access when needed.
It has a lower fee than S3, but you will be charged for a retrieval fee.
It is designed to sustain the loss of 2 facilities concurrently.
It is mainly used for larger objects greater than 128 KB kept for atleast 30 days.
It provides low latency and high throughput performance.
It designed for 99.99% availability and 99.999999999% durability

S3 one zone-infrequent access

S3 one zone-infrequent access storage class is used when data is accessed less frequently but requires rapid access when needed.
It stores the data in a single availability zone while other storage classes store the data in a minimum of three availability zones. Due to this reason, its cost is 20% less than Standard IA storage class.
It is an optimal choice for the less frequently accessed data but does not require the availability of Standard or Standard IA storage class.
It is a good choice for storing the backup data.
It is cost-effective storage which is replicated from other AWS region using S3 Cross Region replication.
It has the same durability, high performance, and low latency, with a low storage price and low retrieval fee.
It designed for 99.5% availability and 99.999999999% durability of objects in a single availability zone.
It provides lifecycle management for the automatic migration of objects to other S3 storage classes.
The data can be lost at the time of the destruction of an availability zone as it stores the data in a single availability zone.

S3 Glacier storage class is the cheapest storage class, but it can be used for archive only.
You can store any amount of data at a lower cost than other storage classes.
S3 Glacier provides three types of models:
- Expedited: In this model, data is stored for a few minutes, and it has a very higher fee.
- Standard: The retrieval time of the standard model is 3 to 5 hours.
- Bulk: The retrieval time of the bulk model is 5 to 12 hours.
You can upload the objects directly to the S3 Glacier.
It is designed for 99.999999999% durability of objects across multiple availability zones.

Performance across the Storage classes

	S3 Standard	S3 Standard IA	S3 One Zone-IA	S3 Glacier
Designed for durability	99.99999999%	99.99999999%	99.99999999%	99.99999999%
Designed for availability	99.99%	99.9%	99.5%	N/A
Availability SLA	99.9%	99%	99%	N/A
Availability zones	>=3	>=3	1	>=3
Minimum capacity charge per object	N/A	128KB	128KB	40KB
Minimum storage duration charge	N/A	30 days	30 days	90 days
Retrieval fee	N/A	per GB retrieved	per GB retrieved	per GB retrieved
First byte latency	milliseconds	milliseconds	milliseconds	Select minutes or hours
Storage type	Object	Object	Object	Object
Lifecycle transitions	Yes	Yes	Yes	Yes