Glossary OS

Plain meaning

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A byte ordering convention where the least significant byte is stored at the lowest memory address. Solana uses little-endian byte order for all on-chain data serialization (Borsh defaults to little-endian), matching the native byte order of x86/ARM CPUs that run validators. When manually reading or writing multi-byte integers from account data, developers must use little-endian functions (e.g., u64::from_le_bytes in Rust, readUInt32LE in Node.js).

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Serialization, memory, data structures, and core engineering basics.

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Little-Endian (little-endian)
Category: Programming Fundamentals
Definition: A byte ordering convention where the least significant byte is stored at the lowest memory address. Solana uses little-endian byte order for all on-chain data serialization (Borsh defaults to little-endian), matching the native byte order of x86/ARM CPUs that run validators. When manually reading or writing multi-byte integers from account data, developers must use little-endian functions (e.g., u64::from_le_bytes in Rust, readUInt32LE in Node.js).
Related: Borsh, Serialization / Deserialization, Account Data

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Borsh

Binary Object Representation Serializer for Hashing—the standard serialization format for Solana program data. Borsh produces deterministic, compact binary encodings with a fixed schema. It's used by Anchor for all account and instruction data serialization/deserialization. Borsh supports structs, enums, vectors, and other Rust types.

Open term

Branch

Serialization / Deserialization

The process of converting in-memory data structures to bytes (serialization) and back (deserialization) for on-chain storage. Solana programs primarily use Borsh, though some use bincode or custom formats. Anchor's #[account] macro auto-derives Borsh serialization. Incorrect deserialization (e.g., missing length checks) is a common vulnerability class.

Open term

Branch

Account Data

The byte array stored in an account that holds program-specific state. Data is typically serialized using Borsh and must be explicitly allocated at account creation. The maximum data size is 10MB. Programs are responsible for defining and managing their own data layout, including discriminators for type identification.

Account

Open term

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Programming Model

Borsh

Binary Object Representation Serializer for Hashing—the standard serialization format for Solana program data. Borsh produces deterministic, compact binary encodings with a fixed schema. It's used by Anchor for all account and instruction data serialization/deserialization. Borsh supports structs, enums, vectors, and other Rust types.

Open term

Programming Model

Serialization / Deserialization

The process of converting in-memory data structures to bytes (serialization) and back (deserialization) for on-chain storage. Solana programs primarily use Borsh, though some use bincode or custom formats. Anchor's #[account] macro auto-derives Borsh serialization. Incorrect deserialization (e.g., missing length checks) is a common vulnerability class.

Open term

Programming Model

Account Data

The byte array stored in an account that holds program-specific state. Data is typically serialized using Borsh and must be explicitly allocated at account creation. The maximum data size is 10MB. Programs are responsible for defining and managing their own data layout, including discriminators for type identification.

Open term

Programming Fundamentals

Lock-Free Data Structure

Concurrent data structure where threads make progress without mutual exclusion locks, using atomic operations (CAS, fetch-and-add) instead. Eliminates lock contention and deadlocks. Firedancer uses lock-free data structures extensively to achieve high-throughput parallel transaction processing across CPU cores.

Open term

Related terms

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Programming Modelborsh

Borsh

Binary Object Representation Serializer for Hashing—the standard serialization format for Solana program data. Borsh produces deterministic, compact binary encodings with a fixed schema. It's used by Anchor for all account and instruction data serialization/deserialization. Borsh supports structs, enums, vectors, and other Rust types.

Open term

Programming Modelserialization

Serialization / Deserialization

The process of converting in-memory data structures to bytes (serialization) and back (deserialization) for on-chain storage. Solana programs primarily use Borsh, though some use bincode or custom formats. Anchor's #[account] macro auto-derives Borsh serialization. Incorrect deserialization (e.g., missing length checks) is a common vulnerability class.

Open term

Programming Modelaccount-data

Account Data

The byte array stored in an account that holds program-specific state. Data is typically serialized using Borsh and must be explicitly allocated at account creation. The maximum data size is 10MB. Programs are responsible for defining and managing their own data layout, including discriminators for type identification.

Open term

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Programming Fundamentals

Rust

A systems programming language emphasizing memory safety, zero-cost abstractions, and concurrency without a garbage collector. Rust uses an ownership model with borrow checking at compile time to prevent data races and null pointer bugs. It is the primary language for Solana program development (via Anchor or native solana-program crate) and the Agave validator client.

Open term

Programming Fundamentals

TypeScript

A statically typed superset of JavaScript that compiles to plain JavaScript. TypeScript adds type annotations, interfaces, generics, and enums to catch errors at compile time. It is the standard language for Solana client-side development—wallet adapters, dApp frontends, test suites, and SDK interactions (web3.js, Anchor client) are typically written in TypeScript.

Open term

Programming Fundamentals

JavaScript

The ubiquitous scripting language for web development, running in browsers and Node.js. JavaScript is dynamically typed and event-driven. Most Solana dApp frontends and scripts use JavaScript/TypeScript with libraries like @solana/web3.js. Node.js enables server-side JS for backend services, indexers, and bot development.

Open term

Programming Fundamentals

Node.js

A JavaScript runtime built on Chrome's V8 engine that enables server-side JavaScript execution. Node.js uses an event-driven, non-blocking I/O model. In the Solana ecosystem, Node.js is used for: running Anchor tests (Mocha/Jest), backend services, transaction bots, indexers, and CLI tools. npm/yarn/pnpm manage JavaScript package dependencies.

Open term