Braintree is a payment processing platform from PayPal that lets businesses accept and manage payments online and in mobile apps.

Payment methods - Credit and debit cards, PayPal, Venmo in the US, Apple Pay, Google Pay, and local payment methods.
Global reach - Processing in more than 200 markets with payouts to 200-plus markets in over 50 currencies.
Security and compliance - Validated Level 1 PCI DSS provider with checkout interfaces that meet SAQ-A requirements.
Sandbox - A test environment to try processing, subscriptions, and the API before applying for an account.
Payouts - Send payments to sellers and service providers around the world from one provider.
Fraud tools - Adaptive fraud screening and payment orchestration across gateways.

It is used by online businesses and marketplaces that need cards, PayPal, wallets, and local methods through a single integration with developer SDKs.