Each block can be connected in multiple ways and joined one on top of the other, side by side, or perpendicularly, meaning you can build in a variety of ways for a variety of uses. They connect with by an interference fit. You can slide them together quite easily with a little wiggle.

They then stay together with a strong grip…..then if you want to take them apart, pull each block apart with another little wiggle and hey presto! The blocks are reset for you to reconfigure into another product… or for another project.