# Explaining JSON Web Token (JWT) To a 10 Year Old Kid

Source: https://blog.bytebytego.com/p/ep69-explaining-json-web-token-jwt
Kiwi News: https://news.kiwistand.com/stories/Explaining-JSON-Web-Token-JWT-To-a-10-Year-Old-Kid?index=0x64bc38848b9654cb3645a8a7f6935a20c9295f59ff2e2ad15ce978b500c860b7699f2bbc
Submitted by accountless.eth on 2023-07-22 UTC, 1 upvote, 0 comments

## Summary

This digest from ByteByteGo's system design refresher covers several topics, with a feature on JWTs, Docker, server types and Linux learning paths. The JWT explanation says a token has three parts: a header describing the box type and how it is secured, a payload carrying the message such as a name or age, and a signature made with a secret code that prevents tampering without the sender's knowledge. The Docker section, by guest author Rohit Sehgal, describes three components: the Docker client, the Docker host daemon, and registries such as Docker Hub. It lists six steps for "docker run", from pulling the image to starting the container. The newsletter also promotes its own Substack, which it says has 500,000 readers.

## Article

This week’s system design refresher:

DevOps vs. SRE vs. Platform Engineering (Youtube video)

Explaining JSON Web Token (JWT) to a 10-year-old Kid

How does Docker work?

Top 6 most commonly used Server Types

Learning Linux system

Feature your product on Substack

Imagine you have a special box called a JWT. Inside this box, there are three parts: a header, a payload, and a signature.

The header is like the label on the outside of the box. It tells us what type of box it is and how it's secured. It's usually written in a format called JSON, which is just a way to organize information using curly braces { } and colons :

The payload is like the actual message or information you want to send. It could be your name, age, or any other data you want to share. It's also written in JSON format, so it's easy to understand and work with.

Now, the signature is what makes the JWT secure. It's like a special seal that only the sender knows how to create. The signature is created using a secret code, kind of like a password. This signature ensures that nobody can tamper with the contents of the JWT without the sender knowing about it.

When you want to send the JWT to a server, you put the header, payload, and signature inside the box. Then you send it over to the server. The server can easily read the header and payload to understand who you are and what you want to do.

Over to you: When should we use JWT for authentication? What are some other authentication methods?

Guest post by Rohit Sehgal.

The diagram below shows the architecture of Docker and how it works when we run “docker build”, “docker pull” and “docker run”.

There are 3 components in Docker architecture:

Docker client The docker client talks to the Docker daemon.

Docker host The Docker daemon listens for Docker API requests and manages Docker objects such as images, containers, networks, and volumes.

Docker registry A Docker registry stores Docker images. Docker Hub is a public registry that anyone can use.

Let’s take the “docker run” command as an example.

Docker pulls the image from the registry.

Docker creates a new container.

Docker allocates a read-write filesystem to the container.

Docker creates a network interface to connect the container to the default network.

Docker starts the container.

Web Server: Hosts websites and delivers web content to clients over the internet

Mail Server: Handles the sending, receiving, and routing of emails across networks

DNS Server: Translates domain names (like bytebytego. com) into IP addresses, enabling users to access websites by their human-readable names.

Proxy Server: An intermediary server that acts as a gateway between clients and other servers, providing additional security, performance optimization, and anonymity.

FTP Server: Facilitates the transfer of files between clients and servers over a network

Origin Server: Hosts central source of content that is cached and distributed to edge servers for faster delivery to end users.

Over to you: Which type of server do you find most crucial in your online experience?

Guest post by Govardhana Miriyala Kannaiah.

System In the system component, we need to learn modules like system APIs, device drivers, I/O, buses, etc.

Memory In memory management, we need to learn modules like physical memory, virtual memory, memory mappings, object allocation, etc.

Process In process management, we need to learn modules like process scheduling, interrupts, threads, synchronization, etc.

Network In the network component, we need to learn important modules like network protocols, sockets, NIC drivers, etc.

Storage In system storage management, we need to learn modules like file systems, I/O caches, different storage devices, file system implementations, etc.

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