As a developer, you have a choice as to what blockchain you use, but very little if any control over the mechanisms that power it.   It's a bit like choosing a country and a language to write your book in.  If it's a smart contract blockchain, move up a level, and you can start to exert more control - for example, you can release a centralized token on a decentralized blockchain, if you so choose. But there are still some fundamental things that you will be tied to, if you want your contract to have traction.  Similarly, as a writer you can bend the rules of grammar or coin new words, but go overboard and your audience will think you're speaking gibberish.  Then there's a third level, namely web3, which acts as a presentation layer. On this layer you can really go to town. There will be more on this in the final video in the series.