This explanation of a hash function and the chain built with it, focuses on the very basics. We hope it can help non-technical people to understand back-step blockchain compared to traditional blockchains. First with a couple of diagrams we explain how a traditional blockchain works. Then we show what proof-of-work means and why it is a problem to our environment. 

Finally we show how the new back-step blockchain solves that problem and how it works.

The output of a hash always looks encrypted. A single change at the input produces a totally different output. A hash can only be calculated from the input to the output, very much like a one way road that goes only in one direction. There is no way to calculate from the output backwards to the input. Output has a defined length, depending on the type of hash you use. The input can be practically any length. The output can be used like a fingerprint, it identifies the input. Again, any change at the input produces a different output hash. This is why hash fingerprints are often used to identify files. A damaged file results in different output. Hash of files is something virus scanners use to detect modifications. 

The next idea is chain hash operations. Output of one hash is used as input of the next hash. In practice you can make such chains very long and you will not find duplicated hash outputs. 

See from hash chain to blockchain