Are "rather than" and "instead of" exchangeable?

Question

i am learning this Stanford course

the professor is saying

x-ray in the hospital is a digital image rather than a physical piece of film

it seems that "rather than" could be substituted by "instead of" in this sentence.

are "rather than" and "instead of" exchangeable?

Answer 1

"instead" implies that one item must be used instead of the other.

"rather than" implies that one material means "one of the two items is closer to the truth / reality than the other".

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"Instead" is associated usually with "to use" (or similar):

Use X instead of Y

Drink water instead of alcohol

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"Rather than" is associated usually with "to be" (or similar):

A is B rather than C

x-ray in the hospital is a digital image rather than a physical piece of film

Choose to be healthy rather than to be beautiful