Reading is a complex skill that involves the integration of several cognitive processes, including phonemic awareness (the ability to manipulate and identify individual sounds in spoken words), phonics (the relationship between sounds and written letters), fluency (the ability to read smoothly and accurately), vocabulary (word meanings), and comprehension (the ability to understand the meaning of what is being read).

1. Phonemic awareness: This refers to the ability to manipulate and identify individual sounds (phonemes) in spoken words. This is an important foundation for learning to read and write, as it helps children to understand that spoken words are made up of individual sounds.

2. Phonics: This refers to the relationship between sounds and written letters. Children who are strong in phonics are able to use the sounds of individual letters and letter combinations to decode (sound out) and encode (spell) unfamiliar words.

3. Fluency: This refers to the ability to read smoothly and accurately, with appropriate pacing and expression.

4. Vocabulary: This refers to the knowledge of words and their meanings. A strong vocabulary is important for reading comprehension, as it helps readers to understand the meaning of unfamiliar words.

5. Comprehension: This refers to the ability to understand the meaning of what is being read. Good comprehension involves being able to make connections between new information and prior knowledge, and to draw inferences from the text. It is largely dependent on fluency, background knowledge and vocabulary.

The Science of Reading involves a broad range of research areas, including linguistics, cognitive psychology, education, and neuroscience, and has helped to improve our understanding of how people learn to read and the factors that contribute to reading success.