You'll see many people use steem when they should use steemit and vice versa. Is it just a simple mistake of expression or not knowing what each of them stands for?
I believe it's a bit of both, but mostly a confusion based on not understanding what each of them really is.
So, let's try to dissipate the confusion here, shall we?
I will start by saying that
Steem is the blockchain on which every other applications such as steemit, dlive, dtube, zappl, steepshot, dmania, busy and others work.
In that respect, Steem is similar to bitcoin's blockchain, but of course it also has its own characteristics which make it unique in the blockchains ecosystem.
If, for example, someone posts a video on dtube, it is really posted on the Steem blockchain, and all applications which use the blockchain have access to it. That's why the video also shows up on steemit.
Each application can choose what to show and what not to show from what is posted on the blockchain. For instance, I posted earlier an image on steepshot. This application won't show blogs from steemit or videos from dtube, because that's how it was designed to be.
Here's another example: I'm writing this post on , and it's the first time I write a post using busy instead of steemit. But I want to make a distinction between where the information is really stored - on the Steem blockchain - and the front view of the information, which are the different apps we use to present it in a way which is more pleasant to our human eyes and more suitable for the purpose of the application.
Let's take this a step further with a comparison to something you already are familiar to. Now, if on the Steem blockchain there's an image posted with steepshot, you can view it in steepshot or in steemit or in busy or in other app. If you have an image on your computer at home, you can choose to edit it with one image editor or another. This image is still stored in your computer's system file (blockchain in our case), regardless which editor you choose.
Something else that may add up to the confusion between Steem and steemit is the fact steemit also has a wallet, where you can check your balances and your history of transactions. You can even access an internal market.
But keep in mind that all these operations still take place on the blockchain.
To understand it better, you can look at steemd.com/@username, where you replace "username" with your account name. All the information listed there is taken directly from the Steem blockchain (in reversed chronological order).
Smart Media Tokens (SMT)
The difference between steem and steemit will become even more obvious with the release of what's called Smart Media Tokens or "SMT" in short.
While now you can use different apps to view content in particular ways, after SMT will be embraced by more businesses, each of them will have the possibility to create its own coin. And all of them working on the same steem blockchain.