A Class 10 memory card refers to a type of secure digital (SD) card commonly used in devices such as cameras, smartphones, and tablets to store data. Here's what the specifications typically mean:

- **Capacity**: 64GB/128GB indicates the amount of storage space available on the card, which is 64/128 gigabytes.

- **Class 10**: This refers to the minimum data transfer speed of the card. Class 10 cards have a minimum sequential write speed of 10 megabytes per second (MB/s). This speed is suitable for recording full HD (1080p) video and high-resolution photos without issues like stuttering or dropped frames.

When choosing a memory card, it's essential to consider both the capacity and the speed class to ensure it meets the requirements of your device, especially if you plan to use it for recording video or storing large files.