There are many ways to segment a very large number of optical communication products, but the simplest seems to be putting mainstream “Optical Transceivers”, both pluggable and soldered variants, into one large grouping for searching your needs. This category includes the familiar 1x9, SFF, SFP, QSFP and CXP products, as well as some of the newer market entries, such as CFP2, QSFP-DD and more. This category allows the optical fiber to be inserted and removed as needed by the end user.
Another grouping are the Active Optical Cables (AOCs), which have the optical fiber permanently embedded in each end, similar to Direct Attach Copper (DAC) cables common in the industry. AOCs work very well for short reach links where the electrical and mechanical flexibility of optical fiber is required.
Finally, a third grouping is for Mid-Board mounted (aka. Embedded Optical Modules) which are mounted away from the host system back panel, closer to internal ASICs, for enabling tight optical I/O clusters and enhanced thermal management solutions. Perfect for High Speed Interconnects, high density server interconnects, chassis cabled optical backplanes ... and any other application requiring special design considerations to optimize system performance.