"Oni chodzą."

Translation: They walk.

[NJG88]

What is the difference between “iść” and “chodzić"?
Do they both mean "to go by foot"? Are they interchangeable?

[JulieBaird1]

I was confused about this also. I'm just learning Polish but what I've figured out is
Oni chodzą = they walk (this is something they do often, but maybe not right at this moment)
Oni idą = they are walking. (they are in doing this now)

If I am wrong, will a native speaker please correct me?

[Jellei]

Generally, yes. Oni chodzą = They walk, they go (on foot); Oni idą = They are walking, they are going (on foot).

With one exception, that "They are walking" (right now, but just walking around, no purpose/direction etc.) is also "Oni chodzą".

[Kamil175561]

As well as that, I have found that iść is continuous. An example would be walking or going to school: idę do szkołę. However you would not use the same verb if you were going to go on a 10 km hike that you were not planning to do again.

[Jellei]

Idę do szkoły :)

I'm not sure what you mean by the hike sentence... that sounds like "Idę" (right now or planning to go once). Or is that exactly what you meant?

[Anthony_Moran]

Would it be incorrect to say "they are walking" ??

[tadjanow]

'They are walking' would be 'Oni idą'.
'Chodzą' implies that the action is repeated.