Frontend
What users see and interact with.
PART I · HOW SOFTWARE WORKS
How Software Works
Understand how a user action moves through frontend, APIs, backend, business logic, and data.
01
What This Module Is About
Most software systems are made of connected parts.
A user interacts with a frontend.
The frontend sends requests to backend services.
The backend processes business rules and works with data.
The result is returned to the user.
This module explains how those parts work together.
02
The Big Picture
User→Client / Frontend→Request→API→Backend
Backend→Business Logic→Database→Response→Frontend Update
A single user action can move through almost every major layer of a software system.
03
Core Concepts
API
How software parts communicate.
Backend
Where requests and business rules are processed.
Business Logic
The rules that decide what the system should do.
Database
Where application data is stored.
Request & Response
How messages move between software components.
04
How Everything Connects
User clicks "Save"→Frontend collects the data→POST /api/knowledge→Backend receives the request→Business logic checks the data→Database saves the record→Backend returns JSON→Frontend shows "Saved"
This one action connects frontend, APIs, backend logic, and data.
Frontendinteraction
APIcommunication
Backendprocessing
Databasestorage
Topics in This Module
${[['Software','Programs and data that help computers perform useful tasks.'],['Application','Software designed for a specific purpose.'],['Client','The side of a system that interacts with a server.'],['Server','A system that receives requests and provides services.'],['Frontend','The part users see and interact with.'],['Backend','The part that processes data and rules.'],['API','A way for software parts to communicate.'],['Request','A message asking for data or an action.'],['Response','The result returned after processing.'],['Business Logic','Rules that decide how the system handles actions.'],['Database','A system used to store application data.'],['JSON','A common format for structured data.'],['Runtime','The environment where software is running.'],['State','Information describing the current condition of a system.']].map(([name,description]) => `${name}${description}Open →`).join('')}