"unit disk" meaning in English

{
  "forms": [
    {
      "form": "unit disks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unit disk (plural unit disks)",
      "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": "topical",
          "langcode": "en",
          "name": "Circle",
          "orig": "en:Circle",
          "parents": [
            "Curves",
            "Shapes",
            "Geometry",
            "Mathematics",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A set of points on a plane whose distance from a given point is less than or equal to one."
      ],
      "id": "en-unit_disk-en-noun--ecWC07u",
      "links": [
        [
          "point",
          "point"
        ],
        [
          "plane",
          "plane"
        ],
        [
          "distance",
          "distance"
        ],
        [
          "less",
          "less"
        ],
        [
          "equal",
          "equal"
        ]
      ],
      "related": [
        {
          "word": "unit circle"
        }
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "Translations",
          "word": "yksikkökiekko"
        }
      ],
      "wikipedia": [
        "unit disk"
      ]
    }
  ],
  "word": "unit disk"
}

{
  "forms": [
    {
      "form": "unit disks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unit disk (plural unit disks)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "unit circle"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Translation table header lacks gloss",
        "en:Circle"
      ],
      "glosses": [
        "A set of points on a plane whose distance from a given point is less than or equal to one."
      ],
      "links": [
        [
          "point",
          "point"
        ],
        [
          "plane",
          "plane"
        ],
        [
          "distance",
          "distance"
        ],
        [
          "less",
          "less"
        ],
        [
          "equal",
          "equal"
        ]
      ],
      "wikipedia": [
        "unit disk"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "Translations",
      "word": "yksikkökiekko"
    }
  ],
  "word": "unit disk"
}