Power versus data
A 240 W USB-C cable can still be slow.
The plug is identical, but power and data are different capabilities. Start with the job: charging only, everyday file transfer, a fast SSD, or a dock and display.
Power is one axis
USB-IF defines 60 W and 240 W power-rating language for eligible USB Type-C cables. A 240 W rating describes the supported power capability; it does not automatically tell you the data rate or whether video works.
Charging cables may use USB 2 data
USB-IF states that USB 2.0 Type-C cables support up to 480 Mbps data operation and physically do not implement the high-speed contacts used for USB 3.2 or USB4 signals. That can be a sensible, lighter construction for charging, but not for a fast SSD or dock.
Data needs its own number
USB-IF consumer language separates USB 5Gbps, 10Gbps, 20Gbps, 40Gbps and 80Gbps. Treat that number as the cable signalling capability—not a guaranteed real-world file-copy speed, which also depends on both connected devices.
Certification is not a family resemblance
A certified logo requires the product to pass the applicable USB-IF compliance testing, appear on the Integrators List and be used under a trademark licence. Evidence for one cable model does not prove a different length or construction.
Read power and data separately
For charging, match cable wattage to the charger and device. For storage, docks or displays, also require the needed data and video capability. usb-c.store keeps those fields separate on every product page.