Lesson 3-1 explained: The Overall Structure of Web Applications

Lesson summary

A web application runs in a browser and is built from three tiers.

Takeaway: Frontend shows and collects, backend decides and processes, database stores and retrieves — three tiers cooperating make a web application work.

Key terms

• Web application
• Frontend
• Backend
• Database
• Three-tier architecture

Textbook page: Arabic book 50 · English book 55

Video lesson

Frontend, backend and database

More videos on this lesson

• Term 1 review (chapters 1–4): AI, HTTPS, web layers and C.R.A.P

Free questions on this lesson

From the textbook question bank. Think of the answer first, then open it.

1. 1. What is a web application, according to the lesson?

   • A program that works only after installing it
   • A server machine that stores pages with no screen
   • An internal network linking one school's devices
   • An application used through a web browser
   Answer

   Correct answer: An application used through a web browser

   A web application is an application used through a web browser.

   1. What is a Web Application? · page 56

2. 2. In the figure, what does the frontend send to the backend?

   • A request
   • A display of results
   • A query to the user
   • Stored data
   Answer

   Correct answer: A request

   In the figure: the frontend sends a request to the backend and receives a response.

   Figure: Three-tier web application architecture · page 56

3. 3. In an SNS, what does the frontend show?

   • Deciding the posts' audience
   • The stored follow relationships
   • The timeline and post screens
   • Controlling the push notifications
   Answer

   Correct answer: The timeline and post screens

   SNS frontend: timelines and post screens, sending input content.

   4. Familiar Web Application Configurations · page 57

Lessons in this chapter 3: Web Applications

1. 3-1 The Overall Structure of Web Applications
2. 3-2 Web Application Communication Methods
3. 3-3 Fundamentals of Frontend Technology