This is a HL7 FHIR server, and as you appear to be accessing this page from a web browser you are seeing a HTML version of the requested resource(s). You can also access this URL from a FHIR client as a ReSTful API call. For more details please see the HL7 FHIR specification.
{
  "resourceType": "ConceptMap",
  "id": "CareConnect-ConditionEpisodicity-1",
  "url": "https://fhir.hl7.org.uk/STU3/ConceptMap/CareConnect-ConditionEpisodicity-1",
  "version": "1.1.0",
  "name": "Concept Map - Condition Episodicity",
  "status": "draft",
  "date": "2018-11-14T00:00:00+00:00",
  "publisher": "HL7 UK",
  "description": "A Concept Map from ValueSet Condition Episodicity Severity to equivalent Snomed CT codes",
  "copyright": "Copyright © 2016 HL7 UK",
  "sourceReference": {
    "reference": "https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-ConditionEpisodicity-1"
  },
  "targetReference": {
    "reference": "https://fhir.hl7.org.uk/STU3/ValueSet/CareConnect-ConditionEpisodeSnCT-1"
  },
  "group": [
    {
      "source": "https://fhir.hl7.org.uk/STU3/CodeSystem/CareConnect-ConditionEpisodicity-1",
      "target": "http://snomed.info/sct",
      "element": [
        {
          "code": "first",
          "display": "First",
          "target": [
            {
              "code": "255217005",
              "display": "First episode",
              "equivalence": "equivalent"
            }
          ]
        },
        {
          "code": "new",
          "display": "New",
          "target": [
            {
              "code": "288527008",
              "display": "New episode",
              "equivalence": "equivalent"
            }
          ]
        },
        {
          "code": "review",
          "display": "Review",
          "target": [
            {
              "code": "303350001",
              "display": "Ongoing episode",
              "equivalence": "equivalent"
            }
          ]
        },
        {
          "code": "end",
          "display": "End",
          "target": [
            {
              "code": "272131007",
              "display": "Old episode",
              "equivalence": "equivalent"
            }
          ]
        }
      ]
    }
  ]
}