What is the payment submissions limit?

what does it mean to 'receive 10 payments'

You may integrate one of the payment gateways available to your form to receive the payments directly from your users. Each submission received with payment is considered as a payment submission and it is the monthly limit. Please refer to the guide below that can help you with payment integrations.

https://www.jotform.com/help/323-Mastering-Payment-Form-Integrations-with-JotForm

Hope this information helps.