Chapter 2: Building Blocks of Fluency and Comprehension. This chapter describes the many component skills and knowledge resources that contribute to reading fluency and reading comprehension. Key component skills addressed include word recognition, orthographic processing, letter-sound correspondences, sight word reading, morphological processing, phonological processing, spelling knowledge and orthographic mapping, syntactic processing, semantic processing, semantic proposition formation, working memory (central executive, phonological loop, episodic buffer), long-term memory, and cognitive executive functions. Other concepts introduced along with component skills include the self-teaching hypothesis, statistical learning, the alphabetic principle, implicit learning, connectionism, lexical access, automaticity, the Lexical Quality Hypothesis, spreading activation, priming effects, word-to-text integration, chunking, meta-linguistic awareness, good-enough parsing, now-or-never processing, chunk-and-pass processing, and usage-based approaches to language learning. The chapter closes with implications for instruction.