我想了解这行的内容，并想问一下是否有人向我解释
config = {
"apiKey": "apiKey",
"authDomain": "projectId.firebaseapp.com",
"databaseURL": "https://databaseName.firebaseio.com",
"storageBucket": "projectId.appspot.com",
"serviceAccount": "path/to/serviceAccountCredentials.json"
}
firebase = pyrebase.initialize_app(config)
db = firebase.database()