https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html
You may be thinking of the /bin and /usr/bin difference, though.
My memory is hazy but I recall the distinction being / vs /usr not /bin vs /sbin.
But I have only ever seen historic references to that argument, from back when dynamic linking was scary and unreliable. I certainly have never encountered that situation in almost 25 years of using Linux.