The solid fraction of a porous medium is not necessarily a homogeneous medium but can be composed of individual components that (all together) form the solid. Neighborhood relations between voxels inside a component differ from those among different components and between component and pore. The Connected Components command analyzes the voxel-to-voxel relations of the solid material and computes the components that build up the solid fraction. A connected component consists of all voxels that are in contact with each other, and which belong to the same phase, the same material, or the same Material ID. Results of the method include the number of defined components (material and background), mean number of components per 2D slice in each spatial direction, and their size with respect to volume visualized as a histogram.