What is dyslexia best defined as?

Dyslexia is best understood as a learning disability that specifically impacts an individual's ability to read and write. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These challenges are not indicative of a person's overall intelligence; rather, they stem from differences in how the brain processes written language.

In contrast, the other responses pertain to different aspects of literacy and education, such as vocabulary assessment, reading comprehension strategies, and grammar instruction, which do not encapsulate the specific nature of dyslexia as a learning disability.