Direct attach cables (DAC) are made of Twinax copper cables with connectors on both ends.
Despite using copper, they can still achieve data-center transmission rates, getting up to 100G as needed.
DAC cables shine in short-range applications. They are most frequently used to connect switches, servers and storage within a rack.
Active optical cables (AOC) are multimode fiber optics cables with SFP connectors on both ends.
This design requires external power to push the signal, which is why ‘active’ is in the name. The signal does not passively run through the fiber optics lines.