Hi. Steemians!
Blockchain is an enabling tech to realize most of digital cryptocurrency like bitcoin, etherium, steem and extra. To the most of peoples, not a IT guy, I think it's not easy to understand what is it and how is it working. One of good news is nice blockchain demo app comes up! It looks well organized with concise intro, javascript code and hands on practice for each step. So you could directly test to make a block and also see which kinds of information are there in the block.
Above picture show the blockchain demo app. For getting started to learn the blockchain, click blockchain demo app first.
When you go to this demo app, to start you need to click the "START DEMO" red botton, which is placed in the right top corner. Then you can see the same snapshot below. Just click the next!
In this step it's let you know what new in 2.0 version of this app. So click the next again!
From this step it start to explain, what is blockchain and what is genesis block. From here if you want you can take a look at the javascript code for each step.
In here it shows each block in blockchain system should have information like index, timestamp, hash, previous hash, data and nonce.
What is index information in the each block? It's the position of the block in the chain. This step below explains it.
Like this you can learn the blockchain by yourself! It consists of 28 steps! Fortunately not so loooong ;) Have a nice journey for blockchain! I hope it helps you to understand better for the blockchain!