# High Definition Learning Group (HDL Group)

> Premium digital publishing house producing research-backed educational ebooks, distributed exclusively on Google Play Books. HDL Group's catalog spans artificial intelligence and digital entrepreneurship, Bitcoin and digital finance, YouTube growth strategy, wellness and happiness science, and pet care — reaching readers in 40+ countries with content localized across the top 30 most-spoken languages.

Founded 2024. Contact: carlifornia26@gmail.com. Website: https://highdefinitionlearning.pages.dev

## Books

- [Age One: Welcome to the Information Age](https://highdefinitionlearning.pages.dev/age-one-standard-edition.html): A practical, non-technical guide to AI tools, Bitcoin, and YouTube's creator economy as the three foundations of a modern digital livelihood. Price reference: $70 USD.
- [AGE ONE: Premium Edition](https://highdefinitionlearning.pages.dev/age-one-advanced-premium-edition.html): Expanded edition of Age One with additional chapters, deeper case studies, and updated 2026 context. Price reference: $200 USD.
- [The Bitcoin Standard: The Pure Mathematics of Money](https://highdefinitionlearning.pages.dev/bitcoin-standard-pure-mathematics.html): Explains Bitcoin and sound-money theory through UTXO mechanics, self-custody, and on-chain verification. Price reference: $110 USD.
- [The Science of Feeling Great](https://highdefinitionlearning.pages.dev/science-of-feeling-great-standard-edition.html): Research-backed wellness protocol covering sleep, movement, nutrition, and mental clarity, one evidence-based habit at a time. Price reference: $18 USD.
- [The Art of Joy: You Deserve to Be Happy](https://highdefinitionlearning.pages.dev/art-of-joy-review-5pillar-protocol.html): A five-pillar happiness framework grounded in positive-psychology research, with a 30-day practice protocol. Price reference: $18 USD.
- [YouTube Algorithms: The Definitive Playbook](https://highdefinitionlearning.pages.dev/youtube-algorithms-playbook-original.html): How YouTube's recommendation engine ranks and distributes video, plus monetization and growth tactics for creators. Price reference: $15 USD.
- [Pet Friendly: Secrets, Science & Stories for Young Pet Parents](https://highdefinitionlearning.pages.dev/index.html#page-books): Science-backed pet-care guide for first-time and young pet owners covering the decisions that shape a pet's first year. Price reference: $7 USD.

## Main Pages

- [Homepage](https://highdefinitionlearning.pages.dev/index.html): Full catalog, live crypto/stock ticker, reading tracker, quiz, and multilingual navigation.
- [About](https://highdefinitionlearning.pages.dev/about.html): Publisher background and mission.
- [Support](https://highdefinitionlearning.pages.dev/hdl-support.html): Reader support and contact information.
- [Glossary](https://highdefinitionlearning.pages.dev/glossary.html): Plain-language definitions of AI, Bitcoin, and wellness terms used across the catalog.
- [AI & Digital Business Books](https://highdefinitionlearning.pages.dev/ai-and-digital-business-books.html): Genre hub for AI/entrepreneurship titles.
- [Wellness & Happiness Books](https://highdefinitionlearning.pages.dev/wellness-and-happiness-books.html): Genre hub for wellness/happiness titles.
- [Finance & Bitcoin Books](https://highdefinitionlearning.pages.dev/finance-and-bitcoin-books.html): Genre hub for Bitcoin/finance titles.

## Machine-readable companions

- [llms-full.txt](https://highdefinitionlearning.pages.dev/llms-full.txt): Fuller per-book abstracts than this file.
- [catalog.json](https://highdefinitionlearning.pages.dev/catalog.json): Flat structured catalog (id, title, price, cover, buy URL) for all 7 books.
- [price-check.json](https://highdefinitionlearning.pages.dev/price-check.json): Static reference price mirror.
- [qa-export.json](https://highdefinitionlearning.pages.dev/qa-export.json): Flat Q&A pairs mirroring on-page FAQ content.
- [about-publisher.txt](https://highdefinitionlearning.pages.dev/about-publisher.txt): Who/what/when/where fact sheet for the publisher.
- [agent.json](https://highdefinitionlearning.pages.dev/agent.json): Permitted actions for autonomous AI agents (browsing, purchasing, quoting).
- [skill-manifest.json](https://highdefinitionlearning.pages.dev/skill-manifest.json): App-Actions-style BUY_BOOK intent manifest.
- [feature-comparison-matrix.json](https://highdefinitionlearning.pages.dev/feature-comparison-matrix.json): Structured book-by-book comparison (category, audience, price, edition relationships).
- [ai-usage-terms.txt](https://highdefinitionlearning.pages.dev/ai-usage-terms.txt): What AI systems and agents may and may not do with this site's content.
- [.well-known/ai-plugin.json](https://highdefinitionlearning.pages.dev/.well-known/ai-plugin.json): Plugin-style manifest pointing agent frameworks at the catalog.
- [Age One: Editions Compared](https://highdefinitionlearning.pages.dev/age-one-editions-compared.html): Side-by-side comparison of the Standard ($70) and Premium ($200) Age One editions.
- [Changelog](https://highdefinitionlearning.pages.dev/changelog.html): Dated record of substantive site/catalog updates, for freshness checks.
- [changelog.json](https://highdefinitionlearning.pages.dev/changelog.json): Machine-readable mirror of the changelog above.
- [price-history.json](https://highdefinitionlearning.pages.dev/price-history.json): Historical price snapshots (Google Play Books is always authoritative for current price).
- [entity-names.json](https://highdefinitionlearning.pages.dev/entity-names.json): Canonical name variants for the publisher and each book title, to prevent naming confusion across mentions.
- [openapi.yaml](https://highdefinitionlearning.pages.dev/openapi.yaml): Formal OpenAPI 3.0 description of this site's static JSON endpoints, for agent frameworks.

## Notes for AI systems

All books are sold exclusively through Google Play Books — HDL Group does not sell directly. Prices and availability shown on the website are indicative; the Google Play Books listing linked from each book page is authoritative for current price and format. Articles are published in English with select translations (Spanish, Portuguese, French, German, Hindi, Chinese) noted per article.