Generally speaking, they are types of direct-connect high-speed Ethernet (HSE) cables, terminated with SFP and/or QSFP transceiver cases at both ends.
Generally speaking, AOC, AEC, AAC and DAC refer to short direct-attach cables for High-Speed Ethernet (HSE) applications, which are terminated with transceiver bodies at both ends, to be directly inserted into servers', routers', switches', and storage appliances' ports (OSFP, QSFPx, SFPx cages). These cost-effective cables are commonly used in Data Center and AI applications and are available in various combinations of straight point-to-point and fan-out configurations, using copper or fiber optics cables.
DAC - Direct Attach Copper cables are passive devices that use coaxial cables to directly connect the xSFP host connectors at both ends. Their reach is only a few meters (depending on signals' speed) and used to connect appliances in the same rack or between adjacent racks. The increasing number of lanes and speed can make these cables very rigid and impractical.
ACC - Active Copper Cables add some signal equalization and amplification electronics at both ends, to improve reach, performance and/or speed over coaxial cables.
AEC - Active Electrical Cables takes signal conditioning a bit further than AAC by adding retiming and CDR functions to improve reach, performance and/or speed over coaxial cables.
AOC - Active Optical Cables have permanently connected xSFP transceiver modules at both ends, supporting longer distances and higher speeds. They are also lighter and more flexible.
Testing, verifying or troubleshooting these passive and active cables require test equipment with two test ports, in order to connect (insert) both ends of the cable under test.
xSFP is used as a generic reference to any OSFP, QSFP-DD, QSFP112/56/28/+, SFP-DD, SFP112/56/28/+ transceiver types.