A canal is a waterway constructed by people, dug for boats or for irrigation: "The barge came up the Grand Union Canal." A channel is a passage water already runs through, or more broadly any route along which something travels: "a deep-water channel", "the news reached us through official channels". Dug from nothing, canal; a path that carries something, channel.
The core difference
Both words describe something water moves along, but they answer different questions. Canal answers "who made it?" — people did, deliberately, end to end. Channel answers "what does it carry?" — and the answer need not be water at all.
Using "canal"
A canal is almost always artificial and almost always named:
- The Suez Canal cut weeks off the voyage.
- They spent the summer restoring a stretch of derelict canal.
- Irrigation canals feed the rice terraces.
The word also has an anatomical sense, for tube-like passages in the body: the ear canal, the birth canal, root canal treatment. Note that canal has essentially no everyday verb use.
Using "channel"
The water sense covers natural straits and the navigable deep part of a river or harbour:
- Ships must keep to the marked channel.
- The English Channel was flat calm.
- The flood carved a new channel through the field.
From there it spreads to any route or medium:
- a television channel; a Slack channel
- Complaints should go through the proper channels.
- a distribution channel; a sales channel
And unlike canal, channel is a productive verb: She channelled her frustration into the garden; The water was channelled away from the foundations.
The test
Ask whether people dug the whole thing. If yes, and boats or irrigation water use it, it is a canal. If the water was already going that way and the passage is natural, dredged or deepened, it is a channel. If nothing wet is involved at all — information, money, products, emotion — it can only be a channel.
The edge cases
Two things blur the line. First, some natural waterways have been so heavily engineered that either word could apply; usage settles it, and usage is fixed by name. Nobody calls the English Channel a canal — though, tellingly, French calls it la Manche and German Ärmelkanal, which is why speakers of those languages often reach for the wrong English word here.
Second, watch the spelling of the verb forms in British English: channelled, channelling with two l's; American English writes channeled, channeling.
Frequently Asked Questions
Is the English Channel a canal?
No. It is a natural strait between England and France, so it is a channel. The Channel Tunnel runs beneath it; the nearby Suez and Panama Canals are artificial, which is why they take the other word.
Is it "root canal" or "root channel"?
Root canal. In anatomy and dentistry, canal is the word for a narrow tube-like passage in the body — ear canal, birth canal, root canal.
Can I say "channel" for a man-made waterway?
Sometimes, if it is a cut for drainage or flow rather than for boats — a drainage channel, for example. But if it was excavated as a navigable route, canal is the natural word, and the name of the waterway will usually tell you which is used.