The two phrases get used as synonyms, and they are not the same kind of thing. One describes what a cable is for. The other describes how well it performs. Confusing them is how people end up buying a cable that fits the description and misses the requirement.
Figure 1: Physical layer twisted pair cabling connecting modern network endpoints.Quick answer
Question | Answer |
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Is Cat6 an Ethernet cable? | Yes. Every Cat6 cable is an Ethernet cable |
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Is every Ethernet cable Cat6? | No. Cat5e, Cat6, Cat6A and Cat8 are all Ethernet cables |
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What does "Ethernet cable" tell me? | What the cable is for, not how fast it goes |
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What does "Cat6" tell me? | The performance category, and therefore the rates and distances |
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What should I search for when buying? | The category, the gauge, the shielding and the jacket rating |
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One is a job description, the other is a rating
"Ethernet cable" answers the question "what is this for". It means a cable intended to carry Ethernet traffic between two pieces of networking equipment, as opposed to a power cord, a video cable or an audio lead.
"Cat6" answers the question "how well does it do it". It is a performance category, defined by a bandwidth figure and a set of crosstalk and loss limits, and it comes with specific rates and distances attached.
So the two phrases operate on different axes. A Cat6 cable is an Ethernet cable the way a pickup truck is a vehicle: the category is inside the description, not next to it.
The categories that are all Ethernet cables
Category | Bandwidth | 1G | 10G | Typical use |
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Cat5e | 100 MHz | 100 m | Not specified | Existing installations, 1G and 2.5G |
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Cat6 | 250 MHz | 100 m | 55 m | Horizontal cabling, access point uplinks |
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Cat6A | 500 MHz | 100 m | 100 m | 10G to the desk, dense bundles |
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Cat7 | 600 MHz | 100 m | 100 m | ISO Class F installations, non-RJ45 interface |
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Cat8 | 1-2 GHz | 100 m | 30 m | 25G and 40G switch links in a rack row |
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Every one of those is an Ethernet cable. The differences between the rows are exactly why "Ethernet cable" is not a specification you can buy against.
What makes a cable an Ethernet cable
Four things, and none of them is a category.
Twisted pairs. Ethernet over copper uses differential signaling on twisted pairs, which is what makes the cable immune to most of the interference around it.
The right count. Four pairs, eight conductors, for anything above 100 Mbps.
Controlled impedance. The cable is built to a characteristic impedance, and the connectors and terminations have to match it. This is why a length of cable joined with a coupler behaves differently from a single run.
A defined performance category. Without a category, the cable has no rated bandwidth and no distance figures, which makes it unsuitable for a design even if it carries traffic fine on a bench.
Where the phrases can mislead
Listings titled "Ethernet cable". Frequently a patch lead in a color, with no category on the page. The cable may be fine. You cannot tell from the listing, and the price often reflects the ambiguity rather than the product.
"Cat6 Ethernet cable" as a search. This is the correct combination, and it is what to search for — the category first, then the use case.
Assumptions about speed. A generic "Ethernet cable" may be a Cat5e lead carrying 1G, and it may be a Cat6 lead, and the listing will not say. If a link needs 2.5G or 5G, the category is the deciding factor.
Assumptions about distance. Many people buying an "Ethernet cable" for a long run are unaware of the 100-meter channel limit, and no product called "Ethernet cable" will tell them. Cat6 has the same limit as every other copper category, with the additional 55-meter restriction at 10G.
Crossover cables, and why they no longer matter much
Older Ethernet wiring required a crossover cable to connect two devices of the same type directly, with the transmit and receive pairs swapped at one end. Modern equipment almost universally supports automatic detection and will sort the pair assignment out in the port, which retired the crossover lead from most toolkits.
The counterpart is that patch leads you buy now are wired straight through, and the pin assignment at both ends is the same. This is why the color code matters at each termination rather than at only one of them.
What to check before you buy
- The category, printed on the jacket or stated in the listing. Without it, there is nothing to design against.
- The conductor. Solid or stranded, and copper or clad. The category assumes solid copper for a permanent link.
- The gauge. 23 AWG is typical for Cat6; thinner cable is a different product.
- The shielding. U/UTP is the default. Shielded constructions only help when the screen is bonded at the ends.
- The jacket rating. What the cable is permitted to be installed in, and whether the space requires a specific rating.
- The length you actually need. Channel length includes the cords, and a longer lead is not a better lead.
Field scenarios
Somebody buying "a long Ethernet cable" for a garage office. The question is the distance. A 95-meter run plus cords exceeds the channel, and no category fixes that. A short fiber run or an intermediate switch is the answer.
An office fit-out specifying "Ethernet cable to each desk". Under-specified. The desk drops should say Cat6, and the specification should say whether the channels require certification.
A home user replacing a worn lead. Any Cat5e or Cat6 patch lead of the right length will do the job. This is the case where the generic phrase is adequate, because 1G at a few meters is not a demanding ask.
FAQ
Is Cat6 better than Ethernet?
The comparison does not work. Cat6 is a type of Ethernet cable. The meaningful comparison is Cat6 against another category, such as Cat5e or Cat6A.
Is a Cat6 cable always an Ethernet cable?
Yes. The category is defined for Ethernet data transmission over twisted pairs.
Can I use a Cat6 cable as a phone cable?
It will carry telephony and it is often used for that, though a dedicated voice cable is cheaper if data is not required at that outlet.
Is Cat6 the same as RJ45?
No. RJ45 is the connector. Cat6 is the cable and channel category that a Cat6 channel is built from.
What does "Cat6 Ethernet cable" mean?
A cable that is both an Ethernet cable and rated to the Cat6 category. That is the term to search for.
Do I need Cat6 for home internet?
Not necessarily. Cat5e carries 1G to 100 meters. Cat6 makes sense if the walls are open, if the connection exceeds 1G, or if you want 10G on the shorter runs.
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