A package in Oracle Data Integrator defines a data integration job. A package is created under a project in ODI. It is made up of an organized sequence of steps, each of which can be an ODI Interface or an ODI procedure. You can also create other steps directly within a package.
To create a package, you can drag and drop the interface you already create to it. ODI will create a link from the package to the interface, instead of making a copy. Whenever you update the origin interface, all the package reference the interface will have the latest changes. You can use interface from other projects.
You can add other steps like sending email, copying files, or waiting for data to arrive to a package.
Finally, you can also add error handling steps to a package. You can tell ODI what to do when a step fails.
A package has one and only one entry point but can have multiple exit points.