"sealed system" meaning in English

{
  "forms": [
    {
      "form": "sealed systems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "sealed system (plural sealed systems)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Systems theory",
          "orig": "en:Systems theory",
          "parents": [
            "Sciences",
            "Systems",
            "All topics",
            "Interdisciplinary fields",
            "Society",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "There are many types of sealed systems, for example an audio speaker, a printing machine, a heating system, or a grain storage system.",
          "type": "example"
        }
      ],
      "glosses": [
        "Any device with inner workings obscured."
      ],
      "id": "en-sealed_system-en-noun-4VPiSW0k"
    }
  ],
  "word": "sealed system"
}

{
  "forms": [
    {
      "form": "sealed systems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "sealed system (plural sealed systems)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with usage examples",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Systems theory"
      ],
      "examples": [
        {
          "text": "There are many types of sealed systems, for example an audio speaker, a printing machine, a heating system, or a grain storage system.",
          "type": "example"
        }
      ],
      "glosses": [
        "Any device with inner workings obscured."
      ]
    }
  ],
  "word": "sealed system"
}