Qi and prana are routinely treated as equivalents in popular writing. Both name a vital principle, but they developed in separate systems and perform different roles within them.
Both name something that animates
Each term refers to a vital principle understood to animate living things and to be connected with breath, and each is described as flowing through the body along pathways.
Both traditions built practices around regulating that flow, including breath exercises, posture, movement and attention directed to specific locations.
The overlap is real and is why the equation is made, since a practitioner trained in one system recognises a great deal in the other.
The surrounding frameworks differ
Qi is embedded in a system organised around paired opposites, phases and correspondences that extend to seasons, directions, flavours and organs.
Prana sits within a scheme of channels and centres oriented toward contemplative aims, and its functional divisions are described in terms of movement within the body.
Each concept is defined partly by its position in these networks, so translating one term by the other detaches it from what gives it precision.
The pathways are mapped differently
Channel systems in the two traditions do not correspond point for point, and the principal routes, the numbers involved and the locations emphasised are not the same.
Attempts to align the maps produce partial matches, which is what one would expect from independent systems describing bodily experience with different priorities.
Where practices resemble each other, the resemblance is usually at the level of technique rather than of the underlying account of what the technique does.
The aims are not identical
Practices centred on qi are often oriented toward health, longevity and the maintenance of balance, and they sit alongside a substantial medical tradition.
Prana-centred practices in their textual settings are typically oriented toward contemplative goals, with physical benefit described as supporting rather than defining the aim.
Both traditions contain exceptions, and each has strands emphasising the other's priorities, which is one reason the concepts are so easily conflated.
Why the distinction is worth keeping
Merging the terms produces a vague general notion of energy that neither tradition would recognise and that loses the specificity each one worked out.
Keeping them separate also allows genuine comparison, since the interesting question is why two independent systems arrived at partly similar accounts.
Neither term is well served by translation into physical vocabulary, and describing each within its own framework remains the more accurate approach.