Does that mean something special in Windows?
It's a GUID (Globally Unique Identifier).
Because it is a unique string we can be sure that no two backup are generated with the same name.
RFC 4122 - A Universally Unique IDentifier (UUID) URN Namespace
This specification defines a Uniform Resource Name namespace for
UUIDs (Universally Unique IDentifier), also known as GUIDs (Globally
Unique IDentifier). A UUID is 128 bits long, and can guarantee
uniqueness across space and time. UUIDs were originally used in the
Apollo Network Computing System and later in the Open Software
Foundation's (OSF) Distributed Computing Environment (DCE), and then
in Microsoft Windows platforms.
Source A Universally Unique IDentifier (UUID) URN Namespace
GUID's – Global Unique Identifiers
GUID’s are essentially a way to identify an object. However they also
name that object uniquely so that no other object has the same GUID.
Now, these "objects" can be anything from an application, part of the
operating system or a physical device like a graphics card to the
actual computer itself.
Why do we need GUID's..?
Well it is a good idea to define every object on the computer with a
unique identifier (GUID). This is because it is possible to have two
objects on your computer that have the same "name." So by giving both
these objects a unique identifier the computer can distinguish between
Both the Windows operating system and software applications that run
on your computer, require EVERY object referenced in the Registry to
have a unique identity.
Programmers use applications like GUIDGEN.EXE to create these special
identifiers, whereas Windows creates them internally.
The GUID concept is based on the Universally Unique Identifiers
(UUIDs) defined by the Open Software Foundation (OSF) as part of the
Distributed Computing Environment (DCE) - but that is probably more
than you wanted to know!
No matter how many GUID's are created they are ALWAYS unique!
So what do GUID's look like?
Well they are what is called "hexadecimal" numbers - a human-friendly
representation of binary coded values.
Essentially each GUID is made up of 5 groups of characters. Each group
has a set (block) number of characters as follows: 8, 4, 4, 4, and 12.
For example: B96073C9-0E9E-406F-B4A6-620E06242B20