NIFTI image matlab

Good evening,
I look for support because I am explained as the nifti images with matlab. What do the header fields mean? Which variable is the intensity of each pixel? I have the field nii, that contains .img, that contains .hdr. I need the intensity of each pixel relatively to each coordinate (x,y,z). How can i express this in an editor in Matlab?

Thanks for answers.

Here is a nice tutorial on NIFTI in Python:

I would suggest to use Python if you are just getting started, and follow that tutorial. But presumably a Nifti library also exists for Matlab.