A machine that guesses the next word
AI doesn’t read letters: it reads chunks
Before understanding anything, the text is cut into tokens: short words, pieces of long words, punctuation and spaces. Each token becomes a number. To the AI, your sentence is a list of numbers.
Type something and see how it gets cut.
An illustrative, simplified split; every real model uses its own vocabulary of tens of thousands of tokens or more: Grok-1’s has 131,072. ↗
Writing is choosing, word by word
A language model does just one thing, over and over: it looks at the text and works out how likely each next word is. It picks one, adds it and repeats. This is a tiny model, trained right here in your browser on a text about the earlier chapters.
The temperature decides how much it takes risks: low, it always picks the most likely word (and repeats itself); high, it gets creative… and a little crazy.
A toy model (it counts which word follows each pair of words in ~40 sentences). Grok and real models do essentially the same, but with billions of parameters and looking at the whole text, not just the last two words.
xAI was founded in March 2023 and unveiled on July 12. ↗
The first version of the assistant, built into X. Grok 4.7 arrived in September 2026. ↗
How long it took to assemble the Memphis supercomputer, with 100,000 GPUs (2024). ↗
Parameters in the model xAI released with open weights in March 2024. ↗
GB300 chips in use at the end of September 2026, also in Memphis, with 660,000 more planned by year-end. ↗
“Accelerate human scientific discovery”, in the company’s own words. ↗
From a chat to understanding the universe
xAI’s idea: ever larger and more capable models, trained on its own supercomputers. Since February 2026 it has been part of SpaceX, which renamed it SpaceXSI in October. ↗ Here is where each piece stands:
- Conversational assistant (Grok)Operational
- Understanding images and talking by voiceOperational
- Coding agents (Grok Build)Operational
- Supercomputers: Colossus 1 and 2Operational
- Colossus 2 with more than a million GPUsIn development
- An AI that helps discover new scienceConcept
Approximate status as of October 2026; things may have moved on. Grok Voice 3.0 came out on October 14, 2026; Grok Build, in May. ↗