A connector is A connector is a collection of templates that define operations users can call from their ESB configurations to easily access specific logic for processing messages. Typically, connectors are used to wrap the API of an external service. For example, there are several ESB connectors that call the APIs of services like Twitter and JIRA. You can also write your own connector to provide access to other services.
WSO2 ESB provides a variety of connectors that allow your message flows to connect to and interact with services such as Twitter and Salesforce. To download ESB connectors, go to https://store.wso2.com/store. You can also create write your own connector to provide access to other services. Before you use the ESB connectors or a custom connector, you need to add and enable them in your ESB instance.
...