"point focal" meaning in French

{
  "forms": [
    {
      "form": "points focaux",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "point focal m (plural points focaux)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "fr",
          "name": "Optics",
          "orig": "fr:Optics",
          "parents": [
            "Physics",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "focal point (point at which rays of light or other radiation converge)"
      ],
      "id": "en-point_focal-fr-noun-zcC2B~wI",
      "links": [
        [
          "optics",
          "optics"
        ],
        [
          "focal point",
          "focal point"
        ]
      ],
      "raw_glosses": [
        "(optics) focal point (point at which rays of light or other radiation converge)"
      ],
      "synonyms": [
        {
          "word": "foyer"
        }
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "engineering",
        "natural-sciences",
        "optics",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/pwɛ̃ fɔ.kal/"
    }
  ],
  "word": "point focal"
}

{
  "forms": [
    {
      "form": "points focaux",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "point focal m (plural points focaux)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "French countable nouns",
        "French entries with incorrect language header",
        "French lemmas",
        "French masculine nouns",
        "French multiword terms",
        "French nouns",
        "French nouns with red links in their headword lines",
        "French terms with IPA pronunciation",
        "fr:Optics"
      ],
      "glosses": [
        "focal point (point at which rays of light or other radiation converge)"
      ],
      "links": [
        [
          "optics",
          "optics"
        ],
        [
          "focal point",
          "focal point"
        ]
      ],
      "raw_glosses": [
        "(optics) focal point (point at which rays of light or other radiation converge)"
      ],
      "synonyms": [
        {
          "word": "foyer"
        }
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "engineering",
        "natural-sciences",
        "optics",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/pwɛ̃ fɔ.kal/"
    }
  ],
  "word": "point focal"
}