Caching Levels & Hierarchy
Discover the different levels where caching can occur, from browser to application to database, and how they form a hierarchy.
Caching Levels & Hierarchy is a free Caching Strategies: Redis + CDN + Edge Computing lesson on CoddyKit — lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Caching Strategies: Redis + CDN + Edge Computing learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Intro to Caching Layers
Like a restaurant prepping common dishes ahead, data is cached at many levels. Together they form a caching hierarchy that optimizes performance layer by layer.
Browser Cache: Personal Storage
The browser cache is the first line: your browser saves static files like images, CSS, and JS, then loads them instantly on your next visit.
Browser Cache: How it Works
Servers control the browser cache with HTTP headers like Cache-Control. For example, max-age=3600 tells the browser to keep a file for one hour.
HTTP/1.1 200 OK
Content-Type: text/css
Cache-Control: max-age=3600, public
ETag: "abc123def456"CDN Cache: Closer to You
Next is the CDN cache: globally distributed edge servers that hold copies close to users, so content travels a much shorter distance.
CDN Cache: Key Benefits
A CDN brings more than speed: lower latency, reduced load on your origin, better reliability if an edge fails, and even DDoS mitigation.
Application Cache: Server-Side Speed
The application cache lives on your server, managed by your code. It holds dynamic-but-stable data — in memory or in a store like Redis or Memcached.
Database Cache: Query Speed
Closest to the raw data sits the database cache: built-in mechanisms that cache query results and hot data blocks, avoiding repeated disk reads.
The Caching Flow
A request flows through the hierarchy: browser, then CDN edge, then application cache, then the database — each layer answers if it can before passing it on.
Why Multi-Layer Caching?
Multi-layer caching is strategic: each layer handles its own content, distributing load while adding resilience, scalability, and lower infrastructure cost.
Quick Check
Understanding the caching hierarchy is key!
Which of the following caching layers is typically the closest to the end-user?
Recap: Your Caching Journey
You explored the caching hierarchy: browser, CDN, application, and database caches — each speeding apps and improving experience in its own way.
Frequently asked questions
Is the “Caching Levels & Hierarchy” lesson free?
Yes — the full text of “Caching Levels & Hierarchy” is free to read here on the web, and the Caching Strategies: Redis + CDN + Edge Computing course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Caching Strategies: Redis + CDN + Edge Computing course, upgrade to CoddyKit PRO.
What will I learn in “Caching Levels & Hierarchy”?
Discover the different levels where caching can occur, from browser to application to database, and how they form a hierarchy. You practise Caching Strategies: Redis + CDN + Edge Computing with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Caching Strategies: Redis + CDN + Edge Computing?
No prior experience is required. Caching Strategies: Redis + CDN + Edge Computing on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Caching Levels & Hierarchy” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Caching Strategies: Redis + CDN + Edge Computing lesson?
Yes. Every Caching Strategies: Redis + CDN + Edge Computing lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Introduction to Caching
- Benefits of Caching
- Caching Levels & Hierarchy
- Measuring Cache Effectiveness