Is there a difference between walking two steps forwards and just zoom in?

[windwaver]

Its harder to keep still at longer focal length, so ur pic maybe blur.

If you're referring to DOF, it's different from a blur picture

 

[deathrequiem]

If you're referring to DOF, it's different from a blur picture

i think he referring to the fact that whatever vibrations in our hands is multiplied at longer focal lengths

 

[Akatsuki]

that would be some perspective difference. Nonetheless, i can't zoom as i use prime lens 90% of the time

 

[shelomoh]

I am using zoom lens 99% of the time. Is there a difference of IQ( or whatever you can think of) if I take a photo of an stand-still object eg 1) using 105mm focal length and 2) I walk eg two steps forward using eg 80mm(same lens). (Assume I acheive the composition, able to reach the object and Ignore lightings/ISO and DOF and nothing tricky about the still object)

Depends on the lens. Different lens perform differently. Even same lens (only applicable to zoom lens) perform differently at different focal length.

Therefore, know your lens well, and push it to it's limits to get the shot you want. Which is why primes are easier to use but troublesome to swap.