What is a key use of a hologram on bank cards?

A hologram on bank cards is primarily used to create a three-dimensional image for security purposes. This method leverages the unique visual properties of holograms, which can show a 3D image when viewed from different angles. This feature not only enhances the aesthetic appeal of the bank cards but, more importantly, serves as a deterrent against counterfeiting and fraud. Holograms are difficult to replicate accurately, making them effective in verifying the authenticity of a card.

The other options do not accurately reflect the primary role of holograms. While user data storage is a function of magnetic stripes or chips on the card, transaction history display is associated with digital banking interfaces rather than physical card features. Similarly, digital banking is facilitated through secure online channels, not through the use of holograms on physical cards. The addition of a hologram primarily addresses security by providing a visual method for card verification.