Object storage is a data storage architecture that manages data as distinct units, called objects. Unlike file systems that organize data in a hierarchical directory structure (folders and files), or block storage which manages data as fixed-size blocks, object storage systems treat each piece of data as a self-contained object.

Each object typically includes:

• The data itself: This could be an image, video, document, backup file, or any other type of unstructured data.
• Metadata: This is descriptive information about the data. Standard metadata might include the object's name, size, type, and creation date. Crucially, object storage also allows for extensive, customizable metadata, which can be very powerful for indexing, searching, and managing data at scale.
• A unique identifier: Each object is assigned a globally unique ID (often a URI or URL) that allows applications to directly access it over a network, typically using HTTP-based APIs.

A BLOB, which stands for binary large object, refers to a collection of binary data stored as a single entity. The term "binary" signifies that the data can be anything; it's not restricted to text or specific formats. It could be an executable file, an image, audio or video content, a compressed archive, a database backup, or any other type of digital information. The "large" part of the name indicates that BLOBs are typically used for files that are too big to be conveniently or efficiently stored directly within a traditional database field alongside structured data.

Therefore, binary large object storage is essentially the practice of storing these BLOBs as individual objects within an object storage system. Instead of embedding a large video file directly into a database record, for example, you would store the video file in an object storage system and then store a reference (the unique identifier or URL of the object) to that BLOB in your database.

Object storage services that host BLOBs often provide different storage classes or tiers, categorized by their access frequency, retrieval times, and cost. These tiers can help organizations optimize storage costs based on how data is used. Common types include:

Designed for frequently accessed data that requires low latency and high throughput. This tier can be suitable for active website content, mobile application data, or data being actively processed by analytics workloads. It typically has higher storage costs but can help lower access costs.

Intended for data that is accessed less frequently (for example, once a month) but still needs to be readily available when requested. It can offer lower storage costs than standard storage but may have slightly higher access costs or per-retrieval fees. This is ideal for long-term backups, data archiving where occasional quick access is needed, or disaster recovery files.

Built for long-term data archiving, compliance, and preservation where data is rarely accessed (for example, once a year or less). This tier can provide low storage costs. Retrieval times can be longer, ranging from minutes to hours, and access costs may be higher. This can be suitable for regulatory archives or data that needs to be preserved for historical purposes but isn't needed for day-to-day operations.

Some providers offer even colder tiers for data that is extremely rarely accessed and can tolerate longer retrieval times (for example, many hours). These tiers offer the absolute lowest storage costs.

The versatility and scalability of BLOB storage can make it suitable for a wide array of applications across various industries: