Literacy is the ability to use the symbols of a writing system. It is the ability to interpret what the information symbols represent, and to be able to re-create those same symbols so that others can derive the same meaning. Illiteracy is not having the ability to derive meaning from the symbols used in a writing system. Dyslexia refers to a cognitive difficulty with reading and writing. It is defined as brain-based type of learning disability that specifically impairs a person's ability to read.[9] The term dyslexia can refer to two disorders: developmental dyslexia[10][11][12][13] which is a learning disability; alexia (acquired dyslexia) refers to reading difficulties that occur following brain damage, stroke, or progressive illness.[14][15]
Major predictors of an individual's ability to read both alphabetic and nonalphabetic scripts are phonological awareness, rapid automatized naming and verbal IQ.[16]