What is UUID?
UUID stands for "Universally Unique Identifier." It is a 128-bit value used to uniquely identify information in a computer system or network. UUIDs are standardized and widely used in various software systems to ensure that each generated identifier is globally unique.
A UUID is represented as a sequence of 32 hexadecimal digits, typically separated into five groups with hyphens. For example, a typical UUID looks like this:
There are different versions of UUIDs, and each version has a different method of generation, making them suitable for various use cases:
- **UUID v1**: Generated based on the current timestamp and MAC address, guaranteeing uniqueness across different devices if the MAC address is globally unique.
- **UUID v2**: Deprecated. Originally meant to be generated based on timestamp and MAC address, but with additional fields for security identification and POSIX user ID.
- **UUID v3**: Generated based on a given namespace and name, using the MD5 hashing algorithm.
- **UUID v4**: Randomly generated using a cryptographically secure random number generator, making them suitable for situations where uniqueness is more important than determinism.
- **UUID v5**: Similar to UUID v3 but uses the SHA-1 hashing algorithm instead of MD5.
UUIDs are commonly used in databases, distributed systems, and various software applications to ensure that data can be uniquely identified even in scenarios where different systems or components interact with each other. They play a crucial role in avoiding conflicts and ensuring data integrity in large-scale and distributed systems.