This chapter is the origin point for Thread 10: Encoding.
Encoding is the principle that the same information can be represented in multiple forms. The forms are interchangeable — equivalent — but different forms have different costs for different operations.
The arrow is:
T10 (Encoding) origin → same meaning, different form (Ch 4) → equivalent data representations (Book 2, Ch 12).
The concept here is the logical foundation of encoding: two expressions that always evaluate identically are interchangeable. Which form you use is an engineering decision, not a correctness decision. This exact principle — same meaning, different form, choose based on cost — recurs in data serialization (JSON vs. Protocol Buffers), data encoding (UTF-8 vs. UTF-32), and distributed representation (sharded vs. replicated data).