In SQL Server Data Tools (SSDT) you build packages by using SSIS Designer and save the packages to the file system as XML files (.dtsx files). You can also save copies of the package XML file to the msdb database in SQL Server or to the package store. The package store represents the folders in the file system location that the Integration Services service manages.
If you save a package to the file system, you can later use the Integration Services service to import the package to SQL Server or to the package store. For more information, see Import and Export Packages (SSIS Service).
You can also use a command prompt utility, dtutil, to copy a package between the file system and msdb. For more information, see dtutil Utility.