Data stored in the cloud grows at an exponential pace. To manage costs for your expanding storage needs, it can be helpful to organize your data based on how frequently it will be accessed and how long it will be retained. Azure storage offers different access tiers so that you can store your blob data in the most cost-effective manner based on how it's being used. Azure Storage access tiers include:
Hot tier - An online tier optimized for storing data that is accessed or modified frequently. The hot tier has the highest storage costs, but the lowest access costs.
Cool tier - An online tier optimized for storing data that is infrequently accessed or modified. Data in the cool tier should be stored for a minimum of 30 days. The cool tier has lower storage costs and higher access costs compared to the hot tier.
Archive tier - An offline tier optimized for storing data that is rarely accessed, and that has flexible latency requirements, on the order of hours. Data in the archive tier should be stored for a minimum of 180 days.
Azure storage capacity limits are set at the account level, rather than according to access tier. You can choose to maximize your capacity usage in one tier, or to distribute capacity across two or more tiers.
The default access tier for a new general-purpose v2 storage account is set to the hot tier by default. You can change the default access tier setting when you create a storage account or after it's created. If you don't change this setting on the storage account or explicitly set the tier when uploading a blob, then a new blob is uploaded to the hot tier by default.
Blob Storage Pricing: