model and model category are represented in Json as a link and sysid

I'm using REST message to fetch data between two my pdi's

"model_category": {
            "link": "https://dev*****service-now.com/api/now/table/cmdb_model_category/81feb9c137101000deeabfc8bcbe5dc4",
            "value": "81feb9c137101000deeabfc8bcbe5dc4"
 
  "model": {
            "link": "https://dev*****.service-now.com/api/now/table/cmdb_model/f8fa15df0a0a0b9100a14bd778fb212a",
            "value": "f8fa15df0a0a0b9100a14bd778fb212a"
         },