There's no "they" because its all artificial. A simulation of a conversation. There's also no "knowing" involved. All an LLM really does is guess what to append to the text that is there thus far.

Instruction tuning (and human feedback) make it so that you can have a chat with it. But all it is still doing is predict the next word. Its literally simulating a conversation.

The reason why OpenAI or llama or deepseek appear smart to you is because it continuously gaslights you into believing it actually understands what you're saying.