Basic JavaScript - Record Collection

i dont see where ‘records’ is defined previously.
is it defined when it is first listed in the function?

  **Your code so far**
// Setup
const recordCollection = {
2548: {
  albumTitle: 'Slippery When Wet',
  artist: 'Bon Jovi',
  tracks: ['Let It Rock', 'You Give Love a Bad Name']
2468: {
  albumTitle: '1999',
  artist: 'Prince',
  tracks: ['1999', 'Little Red Corvette']
1245: {
  artist: 'Robert Palmer',
  tracks: []
5439: {
  albumTitle: 'ABBA Gold'

// Only change code below this line
function updateRecords(records, id, prop, value) {
return records;

updateRecords(recordCollection, 5439, 'artist', 'ABBA');
  **Your browser information:**

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Challenge: Basic JavaScript - Record Collection

Link to the challenge:

records gets a reference to recordCollection when it is called with:

updateRecords(recordCollection, 5439, 'artist', 'ABBA');

and the value is given when the function is called with arguments, so the records parameter takes the value of recordCollection, the id of 5439, the prop parameter of 'artist', the value parameter of 'ABBA'