When you place an order: your name, shipping and billing address, email, phone (if provided), and the items you bought. Payment card details go directly to Shopify and the payment processors Shopify partners with — we never see or store your full card number.
When you write to us through the contact form: your name, email, and the message you send. When you sign up for the newsletter (if enabled): just your email.
Automatically when you visit: standard server logs (IP address, browser type, pages visited) and a small set of cookies that keep the cart working and let us see traffic patterns.