"identity function" meaning in English

{
  "forms": [
    {
      "form": "identity functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "identity function (plural identity functions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "Hebrew terms with redundant script codes",
          "parents": [
            "Terms with redundant script codes",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mandarin terms with redundant transliterations",
          "parents": [
            "Terms with redundant transliterations",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Functions",
          "orig": "en:Functions",
          "parents": [
            "Algebra",
            "Calculus",
            "Geometry",
            "Mathematical analysis",
            "Mathematics",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A function whose value is always the same as its independent variable, and for which the codomain equals the domain."
      ],
      "hypernyms": [
        {
          "word": "inclusion function"
        }
      ],
      "id": "en-identity_function-en-noun-RSLydwxd",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "value",
          "value"
        ],
        [
          "independent variable",
          "independent variable"
        ],
        [
          "codomain",
          "codomain"
        ],
        [
          "domain",
          "domain"
        ]
      ],
      "raw_glosses": [
        "(mathematics) A function whose value is always the same as its independent variable, and for which the codomain equals the domain."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "translations": [
        {
          "code": "ca",
          "lang": "Catalan",
          "sense": "A function whose value is always the same as its independent variable",
          "tags": [
            "feminine"
          ],
          "word": "funció identitat"
        },
        {
          "code": "cmn",
          "lang": "Chinese Mandarin",
          "sense": "A function whose value is always the same as its independent variable",
          "word": "恆等式"
        },
        {
          "code": "cmn",
          "lang": "Chinese Mandarin",
          "roman": "héngděngshì",
          "sense": "A function whose value is always the same as its independent variable",
          "word": "恒等式"
        },
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "A function whose value is always the same as its independent variable",
          "word": "identiteettifunktio"
        },
        {
          "code": "he",
          "lang": "Hebrew",
          "sense": "A function whose value is always the same as its independent variable",
          "tags": [
            "feminine"
          ],
          "word": "פונקצית זהות"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "toždéstvennoje otobražénije",
          "sense": "A function whose value is always the same as its independent variable",
          "tags": [
            "neuter"
          ],
          "word": "тожде́ственное отображе́ние"
        },
        {
          "code": "vi",
          "lang": "Vietnamese",
          "sense": "A function whose value is always the same as its independent variable",
          "word": "đồng nhất thức"
        }
      ],
      "wikipedia": [
        "identity function"
      ]
    }
  ],
  "word": "identity function"
}

{
  "forms": [
    {
      "form": "identity functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "identity function (plural identity functions)",
      "name": "en-noun"
    }
  ],
  "hypernyms": [
    {
      "word": "inclusion function"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with non-redundant non-automated sortkeys",
        "Hebrew terms with redundant script codes",
        "Mandarin terms with redundant transliterations",
        "Requests for review of Dutch translations",
        "Requests for review of Hungarian translations",
        "Requests for review of Icelandic translations",
        "Requests for review of Romanian translations",
        "en:Functions",
        "en:Mathematics"
      ],
      "glosses": [
        "A function whose value is always the same as its independent variable, and for which the codomain equals the domain."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "value",
          "value"
        ],
        [
          "independent variable",
          "independent variable"
        ],
        [
          "codomain",
          "codomain"
        ],
        [
          "domain",
          "domain"
        ]
      ],
      "raw_glosses": [
        "(mathematics) A function whose value is always the same as its independent variable, and for which the codomain equals the domain."
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "wikipedia": [
        "identity function"
      ]
    }
  ],
  "translations": [
    {
      "code": "ca",
      "lang": "Catalan",
      "sense": "A function whose value is always the same as its independent variable",
      "tags": [
        "feminine"
      ],
      "word": "funció identitat"
    },
    {
      "code": "cmn",
      "lang": "Chinese Mandarin",
      "sense": "A function whose value is always the same as its independent variable",
      "word": "恆等式"
    },
    {
      "code": "cmn",
      "lang": "Chinese Mandarin",
      "roman": "héngděngshì",
      "sense": "A function whose value is always the same as its independent variable",
      "word": "恒等式"
    },
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "A function whose value is always the same as its independent variable",
      "word": "identiteettifunktio"
    },
    {
      "code": "he",
      "lang": "Hebrew",
      "sense": "A function whose value is always the same as its independent variable",
      "tags": [
        "feminine"
      ],
      "word": "פונקצית זהות"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "toždéstvennoje otobražénije",
      "sense": "A function whose value is always the same as its independent variable",
      "tags": [
        "neuter"
      ],
      "word": "тожде́ственное отображе́ние"
    },
    {
      "code": "vi",
      "lang": "Vietnamese",
      "sense": "A function whose value is always the same as its independent variable",
      "word": "đồng nhất thức"
    }
  ],
  "word": "identity function"
}