In plain words: Think of Inbound Integration as receiving mail into Salesforce (external systems pushing data or Salesforce pulling external data), while Outbound Integration is sending mail out (Salesforce notifying external ERPs, payment gateways, or databases when something happens). Connecting Salesforce to external enterprise systems requires deciding the direction of data flow and the timing of the exchange. Depending on your business process, integrations operate either as inbound requests entering Salesforce or outbound events dispatched to external platforms.
Topic
Integration & APIs
Salesforce Integration & APIs