Cryptocurrency mining is the process that creates new crypto tokens (bitcoin, doge, etc).
This process is secure and can't be manipulated.
Now imagine that you mine a block with 100 tokens. Instead of taking all the 100 tokens for you you get only 90 tokens and 10 goes to a "pool". This is on the source code and those tokens can't be stolen by the miner.
The tokens from that pools are what we, steemit users are getting from posts.
I hope it is clear enough, english is not my mother tongue.
@kranga Does this not mean that mining is much more profitable than posting contents here? Especially when miners get 90% of the coins mined.
Only if you have the proper hardware, crypto mining need specific hardware, like CPUs, GPUs and ASICS, they are expensive and it wastes a lot of power.
Looks like steem just uses CPU, so if you have a good processor on your computer you can gie it a try, you will also need cheap power prices or solar power in order to make profit of mining.