A Processor or Transaction Processor is an entity that handles a transaction on the behalf of the gateway platform.

A Processor Library Factory provides API for creating a processor client based on the processor configuration values.

A Processor Library is an entity used by the gateway service to process transactions

In the context of this library/package a transaction initiator is the entity that produces/creates a transation ( a {TransactionInterface} in our dialect ). Based on system requirements a transaction initiator has name, a list of clients (web service, client application, etc...) and an active or inactive state

In the context on this information technology implementation, an Invoicer Plaform defines an entity that makes request for invoice transactions on the gateway platform. Invoicer Platforms are defines by their name, address, domain, and authorization credentials.

Transaction Refers to a payable entity (Ex: invoice in invoicing system) that have a given reference to identify it. Transaction usually have a countable value, a weight (Ex: Currency in invoicing system), the date and time at which the transaction was created and the status of the transaction