/core-rules)
    * [ Governance ](/docs/latest/contribute/governance)
    * [ Report a Security Vulnerability ](/docs/latest/contribute/report-security-vulnerability)
  * [ Maintain ESLint ](/docs/latest/maintain/)
    * [ How ESLint is Maintained ](/docs/latest/maintain/overview)
    * [ Manage Issues and Pull Requests ](/docs/latest/maintain/manage-issues)
    * [ Review Pull Requests ](/docs/latest/maintain/review-pull-requests)
    * [ Manage Releases ](/docs/latest/maintain/manage-releases)
    * [ Working Groups ](/docs/latest/maintain/working-groups)

#  Glossary

##  Table of Contents

  1. A 
    1. Abstract Syntax Tree (AST) 
  2. C 
    1. Config File (Configuration File) 
    2. Config Array 
    3. Config Object 
  3. E 
    1. ESQuery 
    2. ESTree 
  4. F 
    1. Fix 
    2. Flat Config 
    3. Formatter (Linting) 
    4. Formatter (Tool) 
    5. Formatting (Rule) 
  5. G 
    1. Global Declaration 
    2. Global Variable 
  6. I 
    1. Inline Config (Configuration Comment) 
  7. L 
    1. Legacy Config 
    2. Linter 
    3. Logical Rule 
  8. N 
    1. Node 
  9. O 
    1. Override 
  10. P 
    1. Parser 
    2. Plugin 
    3. Processor 
  11. R 
    1. Report 
    2. Rule 
  12. S 
    1. Selector 
    2. Severity 
    3. Shareable Config (Configuration) 
    4. Static Analysis 
    5. Stylistic (Rule) 
    6. Suggestion 
  13. T 
    1. Type Checker 
  14. V 
    1. Violation 

This page serves as a reference for common terms associated with ESLint.

##  A

###  Abstract Syntax Tree (AST)

A structured representation of code syntax.

Each section of source code in an AST is referred to as a  node  . Each node
may have any number of properties, including properties that store child
nodes.

The AST format used by ESLint is the  ESTree  format.

ESLint  rules  are given an AST and may produce  violations  on parts of the
AST when they detect a  violation  .

##  C

###  Config File (Configuration File)

A file containing preferences for how ESLint should parse files and run  rules
.

ESLint config files are named like ` eslint.config.(c|m)js ` . Each config
file exports a  config array  containing  config objects  .

For example, this ` eslint.config.js ` file enables the ` prefer-const ` rule
at the _error_ severity  :

    
    
    export default [
        {
            rules: {
                "prefer-const": "error",
            },
        },
    ];
    
    
    1  
    2  
    3  
    4  
    5  
    6  
    7  
    

See [ Configuration Files ](../configure/configuration-files) for more
details.

###  Config Array

An array of  config objects  within a  config file  .

Each config file exports an array of config objects. The objects in the array
are evaluated in order: later objects may override settings specified in
earlier objects.

See [ Configuration Files ](../configure/configuration-files) for more
details.

###  Config Object

A  config file  entry specifying all of the information ESLint needs to
execute on a set of files.

Each configuration object may include properties describing which files to run
on, how to handle different file types, which  plugins  to include, and how to
run  rules  .

See [ Configuration Files > Configuration Objects
](../configure/configuration-files#configuration-objects) for more details.

##  E

###  ESQuery

The library used by ESLint to parse  selector  syntax for querying  nodes  in
an  AST  .

ESQuery interprets CSS syntax for AST node properties. Examples of ESQuery
selectors include:

  * ` BinaryExpression ` : selects all nodes of type _BinaryExpression_
  * ` BinaryExpression[operator='+'] ` : selects all _BinaryExpression_ nodes whose _operator_ is ` + `
  * ` BinaryExpression > Literal[value=1] ` : selects all _Literal_ nodes with _value_ ` 1 ` whose direct parent is a _BinaryExpression_

See [ github.com/estools/esquery ](https://github.com/estools/esquery) for
more information on the ESQuery format.

###  ESTree

The format used by ESLint for how to r