Recurring billing
Recurring billing is an arrangement that charges your saved card automatically on a fixed schedule until you cancel it, rather than asking you to decide again each period. Renewal is the default state, not an action you take.
Where you see it
It is set up at checkout whenever you choose a monthly or periodic plan, and afterwards shows in account billing settings as a next-renewal date. Upgrade prompts inside a site usually lead to the same arrangement, even when they are worded as a one-off unlock.
Why it matters
Because silence keeps it running, a plan you stopped using still bills. Advance notice of each renewal varies by operator and may not be sent at all, so note the renewal date and locate the cancellation control yourself instead of waiting for a reminder email to prompt you.