Here's the simple version, without pretending to be a technical one. Claude was trained on an enormous amount of text — books, articles, websites, conversations — and through that process, it learned patterns in how language works: how sentences fit together, how ideas get explained, how questions typically get answered. When you type a message, it uses those learned patterns to generate a response, word by word, aimed at being genuinely helpful and relevant to what you asked.
That's about as deep as you need to go for everyday use, and it's worth being honest that even people who build these systems describe some of the inner workings as not fully understood in fine detail — which is fine, because you don't need the fine detail to use it well, any more than you need to understand internal combustion to drive a car.
One practical thing worth knowing from that explanation: because it's generating a response rather than looking up a stored fact, it can occasionally get something wrong while sounding confident about it. Worth double-checking anything important, the same as you'd fact-check an overconfident acquaintance.
Beyond that, using it is just conversation. On Ramp AI focuses entirely on that practical side. Here's where to look.