SINR = Signal to Interference-plus-Noise Ratio
=power of signal/(power of interference + power of noise)
Whereas SNR = Signal to noise ratio
= power of signal / (power of noise)
As you can see the interference is the difference between the two.
Usually the interference would just be contained in the noise parameter if it is consistent, but if there is specific interference that you want to show in your calculation SINR is used.
You find it more commonly in wireless signal calculations.
يارب تكون الاجابة واضحة يا باشمهندس