8 types of UUID

misc/UUIDTypes.md

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+# Types of UUIDs
+
+There are 8 versions of UUIDs (v1 through v8), each with different generation methods and use cases.
+
+• UUID v1: Timestamp + counter + MAC address
+• UUID v2: Reserved for security IDs (details unknown)
+• UUID v3: MD5 hash of provided data (e.g., DNS, URLs)
+• UUID v4: Random data (most common)
+• UUID v5: SHA1 hash of provided data (e.g., DNS, URLs)
+• UUID v6: Like v1, but sortable by creation time
+• UUID v7: Timestamp + random data
+• UUID v8: Custom implementation
+
+Key points:
+• UUID v4: Generated from random data. Good default choice for most applications.
+• UUID v7: Created from timestamp and random data. Useful for sortable IDs (e.g., database keys).
+• When choosing a UUID version, you'll usually be picking between v4 and v7.
+
+References:
+
+- [8 versions of UUID and when to use them](https://ntietz.com/blog/til-uses-for-the-different-uuid-versions)