And because the spectrum of the discrete time signal, this similar spectrum will periodically repeat if we extended the frequency larger past $f_s$ this kind of the spectrum shown can be exactly the same spectrum in just about every frequency band from $nf_s$ to $(n+1)f_s$ for just about any integer https://bestboyspginsector15gurgaon.blogspot.com/2025/07/modern-boys-pg-in-gurgaon-sector-15.html