Metadata is often this piece of information that can validate or discredit the entire data set.
You can have great knowledge (data) in your hands, but what if you can't understand it? Well, maybe you need a dictionary (metadata).
PS. The book is "The Art of War" by Sun Tzu.
So you have all the data points. Can you link them together to create a story? Often not without additional contextual information - sometimes called metadata.
The value of the message (data) may depend a lot on the information of where does the message come from (metadata).
We are consuming a lot of metadata daily. Data too.
You need metadata to navigate large amounts of data.
It may look the same at first glimpse. But the source and additional attributes can tell you a lot about its value.
Before you consume it you might want to know more about it.
Can you speak data?
Data is treasure, but how do you know where it is burried?
I could tell you all about how metadata is data about data, but I'd rather show you this picture.