What is the difference between 3D volume and 4D volume?

Hi.

I looked around the forum and saw a lot of 4D Volume (nrrd file).

I searched to find out about 4D Volume, but I did not know.

What is the difference between 3D Volume and 4D Volume?

Thank you.

The 4th dimension is often time, but can be diffusion gradients or segmentation. Maybe you can start by looking at the multivolme support. Feel free to follow up if you have more questions.