This is the basic data from Wikipedia. Literally the only use fur that website is basic technical data.
A globally unique identifier (GUID /ˈɡuːɪd/) is a unique reference number used as an identifier in computer software. The term “GUID” typically refers to various implementations of the universally unique identifier (UUID) standard.
GUIDs are usually stored as 128-bit values, and are commonly displayed as 32 hexadecimal digits with groups separated by hyphens, such as:
They may or may not be generated from random (or pseudo-random) numbers. GUIDs generated from random numbers normally contain 6 fixed bits (these indicate that the GUID is random) and 122 random bits; the total number of unique such GUIDs is 2122 (approximately 5.3×1036). Assuming uniform probability for simplicity, the probability of one duplicate would be about 50% if every person on earth as of 2014 owned 600 million GUIDs. The application of the GUID is effectively premised on the assumption that a conflict will never occur, given the number of GUIDs liable to be required over the life of the application. More strictly, the user considers the benefits of its use to outweigh the potential consequences of a conflict, given the probability of that occurrence. Other GUID versions have different uniqueness properties and probabilities, ranging from guaranteed uniqueness to likely duplicates.