Rehydration is the process of moving data from the archive storage tier to an online tier (like hot or cool) so it can be accessed and modified.
The minimum retention period for the Archive tier depends on the provider, with Azure requiring 180 days.
The "Premium Access Tier" is a high-performance tier for cloud storage, such as Azure Blob Storage or Azure Files, that prioritizes low latency and high throughput.
The Cold Access Tier is an online storage option optimized for data that is rarely accessed but requires fast retrieval when needed. It offers lower storage costs than the cool tier, but has higher access costs. Data stored in the cold tier must be kept for a minimum of 90 days and is ideal for scenarios like backups or compliance data that may be accessed infrequently but needs to be immediately available.
The main purpose of the cold tier is to provide the most cost-effective storage for data that is infrequently accessed over the long term. It is used for archiving, backups, and meeting long-term compliance requirements, where retrieval speed is not a priority.