What happens to what you type.
WITHIN A CONVERSATION
It has everything you said available, because the conversation is sent each time.
That is not learning. It is context.
BETWEEN CONVERSATIONS
Generally nothing carries over. A new conversation starts fresh.
DOES IT TRAIN ON MY INPUT
That varies by provider and by plan.
Some use conversations to improve future models. Some do not. Free tiers frequently differ from paid ones.
WHAT TO DO
Check the policy for the service and tier you use.
WHY IT MATTERS
For business use, whether your material could influence a future model is a genuine consideration.
HUMAN REVIEW
Many providers permit staff review of conversations for safety and quality.
Assume anything you type could be read by a person.
THE PRACTICAL POSITION
Do not put anything in that you would mind being retained or read.