問題：
Going through the docs, I encountered:通過文檔，我遇到了：
...you can call functions directly with an HTTP request or a call from the client . ...您可以使用 HTTP 請求或來自客戶端的調用直接調用函數。
there (link in the quote) is a mention about functions.https.onCall .那裏（引用中的鏈接）提到了functions.https.onCall 。
But in the tutorial here , another function functions.https.onRequest is used, so which one should I use and why?但是在這裏的教程中，使用了另一個函數functions.https.onRequest ，那麼我應該使用哪個，爲什麼？ What is the difference/similarity between them?它們之間有什麼區別/相似之處？
Documentation for functions.https is here . functions.https文檔functions.https在這裏。