What does mean by following code nd picture?

Dear Members and Experts/ Seniors Can anyone explain what this code actually refers? Pictures is result of that code kindly explain anyone , is it frequency response or anything else let me know please.

t=0:0.001:2; % 2 secs @ 1kHz sample rate x=chirp(t,0,1,150); % Start @ DC, cross 150Hz at t=1sec F = 0:.1:100; [y,f,t,p] = spectrogram(x,256,250,F,1E3,'yaxis'); % NOTE: This is the same as calling SPECTROGRAM with no outputs. surf(t,f,10*log10(abs(p)),'EdgeColor','none'); axis xy; axis tight; colormap(jet); view(0,90); xlabel('Time'); ylabel('Frequency (Hz)'); [y,fs]=audioread('Mithe Mustafa Tey 5sec.mp3'); NW = round(fs*0.250); [S,F,T,P] = spectrogram(y(1:,NW,[],[],fs); subplot (2,1,1),pcolor(T,F,log10(p)), shading flat, caxis([-6 0] +max(caxis)) colorbar subplot (2,1,2) semilogy(F,P(:,23)) titlw(sprintf('PSD at time: %f',T(23))) xlabel ('Frequency(HZ)')