A consumer consumes things.
A producer produces things and often owns the means of production.
A prosumer is someone who can produce and consume, for example for the first time in history the poor and middle class can own the means of production, e.g. making electricity, desalinating water, etc, a lot cheaper than we can buy it from others.
We will all realise at some point that we can do this once our consciousness is raised. Until then we will continue in the consumer culture where we think that cars and other fancy stuff are more important than owning the means of production.