"user agent" meaning in English

{
  "etymology_text": ": user agent < → δείτε τις λέξεις user και agent",
  "forms": [
    {
      "form": "user agent"
    },
    {
      "form": "en-noun-s",
      "tags": [
        "inflection-template"
      ]
    },
    {
      "form": "user agent",
      "raw_tags": [
        "ενικός"
      ]
    },
    {
      "form": "user agents",
      "raw_tags": [
        "πληθυντικός"
      ]
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Πληροφορική (αγγλικά)",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "συντομογραφία: UA"
        }
      ],
      "glosses": [
        "πράκτορας χρήστη"
      ],
      "id": "el-user_agent-en-noun-eRsJ~RaG",
      "raw_tags": [
        "πληροφορική"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "client application"
    }
  ],
  "word": "user agent"
}

{
  "etymology_text": ": user agent < → δείτε τις λέξεις user και agent",
  "forms": [
    {
      "form": "user agent"
    },
    {
      "form": "en-noun-s",
      "tags": [
        "inflection-template"
      ]
    },
    {
      "form": "user agent",
      "raw_tags": [
        "ενικός"
      ]
    },
    {
      "form": "user agents",
      "raw_tags": [
        "πληθυντικός"
      ]
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Πληροφορική (αγγλικά)"
      ],
      "examples": [
        {
          "text": "συντομογραφία: UA"
        }
      ],
      "glosses": [
        "πράκτορας χρήστη"
      ],
      "raw_tags": [
        "πληροφορική"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "client application"
    }
  ],
  "word": "user agent"
}