#Container Fundamentals

Understand what containers are and why they matter.

#Containers vs VMs

Feature	Containers	VMs
Isolation	Process level	Hardware level
Boot time	Milliseconds	Minutes
Size	MBs	GBs
Overhead	Minimal	Significant
Portability	Excellent	Good

#Container Architecture

diagram

┌─────────────────────────────────────┐
│           Container 1               │
│  ┌─────────────┐ ┌─────────────┐   │
│  │    App      │ │    Libs     │   │
│  └─────────────┘ └─────────────┘   │
├─────────────────────────────────────┤
│        Container Runtime            │
│       (Docker, containerd)          │
├─────────────────────────────────────┤
│           Host OS (Linux)           │
├─────────────────────────────────────┤
│            Hardware                 │
└─────────────────────────────────────┘

#Key Concepts

Concept	Description
Image	Read-only template for containers
Container	Running instance of an image
Registry	Storage for images (Docker Hub)
Layer	Image is built in layers
Volume	Persistent storage
Network	Container networking

#Benefits

Consistency: Same everywhere
Isolation: Process isolation
Portability: Run anywhere
Efficiency: Share OS kernel
Scalability: Easy to scale

[!TIP] Pro Tip: "It works on my machine" is solved by containers!