SPDIF cable same as coaxial cable?

op - you should do some basic google searches and read, or if you don't like to do that, try youtube

you ask soooooo many very basic questions

crusty and yeti have it right

clwinbe hasn’t a clue

here is a tutorial to help educate
https://darko.audio/2018/11/why-isnt-digital-audio-just-ones-and-zeroes/

try this

https://www.youtube.com/watch?v=N66aDb7LZaM&t=23s

if you are running optical spdif the key, an absolute key, is to get a true glass fiber (not plastic) cable - with this, the sq gap is equalized to electrical spdif

there are some reasonably priced ones out there, just search

but know that alot of the ’audiophile’ toslink cables marketed out there as such are still plastic conductor...