It’s measured in tokens. Everything in the conversation, including your messages, files and the AI’s replies, has to fit. When it’s full, older parts get dropped or ignored.
Example
In a very long chat, the AI forgets instructions you gave at the start.
Why it matters to you
If an AI suddenly ignores earlier details, a new conversation with a short summary often fixes it.
Related terms
TokenA small piece of text, often part of a word, that language models read and write./knowledge-base/token/LLM (Large Language Model)An AI model trained on huge amounts of text so it can understand and write language./knowledge-base/llm/ChatbotA program you talk to in a conversation, by typing or speaking./knowledge-base/chatbot/
