Data Services vs Data Integrator - whats the difference??

Hey - i recently installed Data Integrator v11.7. This is now connecting happily to sap. A collegue has recently download the Data Migration Best Practices from SAP.

He was under the impression that would use the DI installation.

However its saying we arent at the right version, we need 12.1 but i cant find any upgrades for DI?

There is something called Data Services which is at version 12.1, whats this in relation to DI?

Will he need to install that in order to use the Best Practice tool?

Thanks

Carston