It's not just about being able to read

Literacy isn’t just the ability to read and write, it is the ability to understand what you are reading as well. One cannot read unless they understand what they are reading. Click "here"

In order to understand a literacy you must know the terminology used. You cannot play baseball without knowing what an out is, or cook without knowing what a cup is. You must be able to understand what is being presented to you in order to be literate. It isn't just about being able to read and write but being able to comprehend the message being conveyed. You maybe able to read a math textbook but that doesn't mean anything if you can't comprehend the math. There is more than being able to read and write.