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Tall, high-resolution PNG posters that explain everyday technology in a simple, friendly way. Print and use them freely for classroom display, lessons, projects, or learning at home. No sign-up required.
📝 Note: the posters themselves are written in Japanese (designed for Japanese elementary and middle school students).
Learning poster explaining QR code settings for students (in Japanese)
QR Code

QR Code Settings

Illustrates how QR codes work — version, error-correction level, and masking — and the trade-off "more robust, but larger."

Learning poster explaining barcode types and settings for students (in Japanese)
Barcode

Barcode Basics

Covers barcode types (JAN/EAN-13, CODE128, CODE39), how a 13-digit JAN works, and tips for clean, scannable codes.

Learning poster explaining IP address and subnet mask for students (in Japanese)
IP Address

IP Address Basics

IP = address, subnet mask = the town boundary. Explains the "/24" notation, DHCP, the gateway, and what each part does.

Learning poster explaining the role and history of HTML (in Japanese)
HTML

HTML Basics

HTML builds the "skeleton" of a web page. Covers tag structure, semantics, and its history since 1991.

Learning poster explaining the role and history of CSS (in Japanese)
CSS

CSS Basics

CSS controls the "look" of a web page. Covers selectors, responsive design, and its history since 1996.

Learning poster explaining the role and history of JavaScript (in Japanese)
JavaScript

JavaScript Basics

JavaScript gives a web page its "behavior." Its role, what it can do, and its history since 1995, in one page.

Learning poster explaining how a web page is displayed (in Japanese)
How the web works

How a Page is Displayed

From entering a URL to seeing the page: the technical flow of DNS → connect → fetch → render, illustrated.

Learning poster explaining common server attacks and defenses (in Japanese)
Security

Server Attacks & Defense

How common attacks work — DDoS, SQL injection, XSS and more — and how to defend against them, from a defender's view.

Learning poster explaining vulnerabilities and CVE management (in Japanese)
Security

Vulnerabilities & CVE

What software vulnerabilities are. CVE IDs, CVSS, and the flow from discovery to fix and disclosure, illustrated.

Learning poster explaining open-source software development and history (in Japanese)
Development

Open Source (OSS) Basics

What OSS is, the GitHub development flow, everyday examples, and its history from GNU and Linux, in one page.

Usage