Lesson 3 of 8
Asking and answering
Show on a big screenA page fills in slowly. The words arrive first. A photo arrives a moment later.
Step 1 of 4
- Your phone. The server. Nothing sent yet.
- Your phone asks: send the words.
- The server answers: here are the words.
- A photo needs its own ask and answer.
A page comes in pieces. A piece is the words, or one photo.
- A request is the message that asks. Your phone sends it.
- A server is a computer that waits for requests and answers them.
- An answer is what comes back. It may be one piece of the page.
Rule: Your phone sends a request. A server sends an answer. Each piece of a page needs its own.
A simple page with words and 3 photos needs 4 requests. The words need 1 request. Each of the 3 photos needs 1. So 1 + 3 = 4.
Watch out!
A slow page does not always mean a slow phone. The trip to the server and back also takes time.
Slide the photos. Count the asks and answers.
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