"one and the same" meaning in English

{
  "etymology_text": ": one and the same < → δείτε τις λέξεις one, and, the και same",
  "forms": [
    {
      "form": "one and the same"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Ιδιωματισμοί (αγγλικά)",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "It’s one and the same.",
          "translation": "Είναι ένα και το αυτό"
        },
        {
          "text": "It’s all one and the same to me if you go or don’t go.",
          "translation": "Ένα και το αυτό μου κάνει πας δεν πας."
        },
        {
          "text": "Jekyll and Hyde were one and the same person.",
          "translation": "Ο Τζέκυλ και ο Χάιντ ήταν ένα και το αυτό πρόσωπο."
        }
      ],
      "glosses": [
        "ένα και το αυτό"
      ],
      "id": "el-one_and_the_same-en-phrase-O8ULe64b",
      "raw_tags": [
        "ιδιωματισμός"
      ]
    }
  ],
  "word": "one and the same"
}

{
  "etymology_text": ": one and the same < → δείτε τις λέξεις one, and, the και same",
  "forms": [
    {
      "form": "one and the same"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        "Ιδιωματισμοί (αγγλικά)"
      ],
      "examples": [
        {
          "text": "It’s one and the same.",
          "translation": "Είναι ένα και το αυτό"
        },
        {
          "text": "It’s all one and the same to me if you go or don’t go.",
          "translation": "Ένα και το αυτό μου κάνει πας δεν πας."
        },
        {
          "text": "Jekyll and Hyde were one and the same person.",
          "translation": "Ο Τζέκυλ και ο Χάιντ ήταν ένα και το αυτό πρόσωπο."
        }
      ],
      "glosses": [
        "ένα και το αυτό"
      ],
      "raw_tags": [
        "ιδιωματισμός"
      ]
    }
  ],
  "word": "one and the same"
}