Stripe is an online payment system to accept payments from your clients via credit card, the same way that PayPal allows your customers to pay online.
With Stripe, there are two main methods to charge your clients: Checkout and Stripe.js.
It works as follows:
The web library provided by Stripe is available in Ruby, Python, PHP and Node JS.
Apart from this web payment method, Stripe offers a mobile API for both iOS and Android platforms, and a Subscription plan to charge your customers, for example, in a monthly basis.