# tree (0-tree.org)

A tree is a plant with a woody trunk, branches, and leaves. People also call family lineages trees, with parents above and children below.

## What a model may hear
- hierarchical data structure (computer science and programming): assume a node with child nodes, used for searching, parsing, or organizing data
- decision tree (machine learning): treat it as a flowchart of binary splits used for classification or prediction
- directory tree (file systems and operating systems): list files and folders in a branching, indented format or navigate nested paths
- parse tree (compilers and linguistics): build a structured representation of grammar from a sentence or code
- Merkle tree (cryptography and blockchains): verify data integrity through a hierarchy of cryptographic hashes

## Where people and models part ways
- Says: "Show me the tree"
  Means: a picture of an oak or pine
  May be taken as: print a file directory listing or ASCII art of nested folders
  Say instead: "Show me a photograph of a tree"
- Says: "Build a family tree"
  Means: a chart of relatives
  May be taken as: generate a data structure with parent and child pointers
  Say instead: "Create a visual family tree diagram with names and dates"
- Says: "The tree is unbalanced"
  Means: a lopsided real tree
  May be taken as: diagnose a binary search tree with uneven left and right subtrees
  Say instead: "The real tree leans to one side"
- Says: "Prune the tree"
  Means: cut branches in a garden
  May be taken as: remove nodes from a decision tree or data structure to reduce complexity
  Say instead: "Prune the actual garden tree"

## Tips
- Say 'real tree' or 'living tree' when you mean a plant
- Say 'decision tree' or 'file tree' when you want the technical structure
- Add 'visual' or 'diagram' when you want a picture, not code
- Specify 'family tree' clearly; models may still offer data structures
- In coding contexts, say 'tree data structure' to avoid ambiguity

## Often confused with
- graph: any connected nodes, not necessarily hierarchical
- forest: a collection of separate trees, in both plain and technical senses
- heap: a tree with a specific ordering rule for fast access
- trie: a tree for storing strings, with nodes as prefixes
- binary tree: a tree with at most two children per node
- bush: a shorter, multi-stemmed plant with no technical meaning