Data structures and encoding
Ethereum creates, stores and transfers large volumes of data. This data must get formatted in standardized and memory-efficient ways to allow anyone to run a node on relatively modest consumer-grade hardware. To achieve this, several specific data structures are used on the Ethereum stack.
Patricia Merkle Tries are structures that encode key-value pairs into a deterministic and cryptographically authenticated trie. These are used extensively across Ethereum's execution layer.
Recursive Length Prefix (RLP) is a serialization method used extensively across Ethereum's execution layer.
Simple Serialize (SSZ) is the dominant serialization format on Ethereum's consensus layer because of its compatibility with merklelization.