Data Transformation Services packages can be stored in one of three storage systems:
Packages saved in COM-Structure Storage are easy to e-mail or distribute through file servers.
Packages saved in SQL Server msdb database are easily accessible to applications that have connected to that server. They have less overhead than files connected to the repository, so are a good choice for packages that need high performance.
Packages saved in Repository are also easily accessible to applications that have connected to that SQL Server installation. They also support providing package metadata to applications and recording data lineage.
Packages saved to Microsoft Repository or to SQL Server storage are both stored in the msdb database, but they are stored in separate sets of system tables.
DTS packages are assigned versions numbers. Versioning allows changes to packages to be tracked and also indicate which version of a package performed a specific transformation.
DTS packages saved in Data Transformation Services files can be encrypted to secure user IDs and passwords.