PES
EN English 한국어 日本語 中文 हिन्दी বাংলা اردو Español Português Français Deutsch Русский العربية Bahasa Indonesia Tiếng Việt ไทย Türkçe

How to enable notifications

Notifications are unavailable in this browser or on this address. Try a supported browser on the secure PES site.

If notifications are blocked, allow them in your browser settings.

  1. Open the site controls beside the address bar, or your browser’s site settings. Set Notifications for this site to Allow.
  2. In your device settings, allow notifications for your browser and check Do Not Disturb or Focus.
  3. Return to PES, reload the page, and use the bell to enable notifications.

On iPhone or iPad, add PES to your Home Screen, open it there, then allow notifications.

My learning progress
  1. How to use AI
  2. Terminal commands
  3. Advanced AI
  4. Vibe coding
  5. AI certification Getting ready
  6. Keyboard
See details
All AI lessons
Stage 3

Text, tokens, and IDs

Learning goal

Separate text pieces from their numeric identifiers.

A tokenizer converts text into pieces called tokens and maps them to IDs in a vocabulary. Tokens may be words, word pieces, characters, or bytes; spaces and punctuation also matter. The same text can have different token counts with different tokenizers.

A closer look

Our toy lab uses a simple word tokenizer, not a production LLM tokenizer. An ID is just a label: ID 8 is not twice the meaning of ID 4. A context window limits how many tokens a model can use; the application may select, summarize, or discard material to fit.

Explain it yourself

If two tokens have adjacent IDs, must their meanings be similar?

Compare with an explanation

No. IDs identify vocabulary entries; their numerical distance does not measure meaning.

You mark this yourself. Nothing is graded here.

Mark this step as understood?

This cannot be undone yet, so mark it only when you really understand.

Marked as understood

You mark this yourself. Nothing is graded here.

Sources and further reading

Guidelines

AI

AI Certification

Study

Vibe Coding

Game

Practice

Tutors

Chat

Forum

Create

Community

More

Glossary

Pick a word you don't know. You'll see a simple explanation and related terms.

No matching term yet.

Pick a term to see its explanation.