A DVI to DVI cable is a type of video cable used to connect devices that have Digital Visual Interface (DVI) ports. This connection is commonly used for transmitting high-quality digital video signals between devices such as computers, monitors, and projectors. The DVI interface supports both digital and analog signals (depending on the type of DVI port) and comes in a few different formats, such as:

1. DVI-D (Digital): This type only supports digital signals and is most common for newer devices like LCD monitors or digital projectors.
2. DVI-I (Integrated): This supports both digital and analog signals, meaning it can connect to both digital and VGA monitors with the right adapter.
3. DVI-A (Analog): This type supports only analog signals and is less commonly used compared to the other two types.

A DVI to DVI cable is typically used to ensure a high-quality connection between two devices with matching DVI ports, offering a clear digital video signal without signal degradation.

If you're looking to purchase a DVI to DVI cable, it's important to check the exact type of DVI ports on both devices to ensure compatibility (e.g., DVI-D to DVI-D, or DVI-I to DVI-I).

Let me know if you need any help finding one or need more details!