S=Slit width/ wavelength
S is value of diffraction.
This formula helps realise both wavelength and slit width have the same impact. If both icnrease by 5 then nothing changes. If they change by different amounts then the amount of diffraction changes
When the width of the slit/gap is decreased, the width of the diffraction interference pattern is incrwaed . When the slit width becomes too small the diffraction fringes become so wide that it becomes difficult to tell apart between the dark and light lines
you should learn to explain it and desribe the patterns of areas of minima and maxima.