NVIDIA has a fantastic reference guide for high-bandwidth cables and connectors: NVIDIA Cable Management Guidelines and FAQ.

Of note,

TransceiverSignalsApplications
QSFP564x50GHDR InfiniBand
200G/400G Ethernet
QSFP-DD8x25G (NRZ)
8x50G (PAM4)
200G Ethernet
Slingshot
OSFP8x25
8x50
8x100
NDR InfiniBand