Adaptation happens when continuing the same studies already started at another university or when changing the curricula at the same university. Thus, adaptation can take place in two situations:
La Validation because of starting other university studies. It occurs when initiating other official university studies different from those already started or finished in the same or in another university. (For example: from Law Graduate Studies to Economics Graduate Studies, from Mathematics Graduate Studies to Physics Graduate Studies, from Social Graduate Diploma to Law Graduate, etc).
The concept of Partial Validation of Foreign Studies is used when it's about to continue the same foreign studies.
Validation of a Foreign Univesity Qualification
In the case of foreign university graduates, you can choose between requesting the Ministry the recognition of the foreign qualification as equivalent to an official Spanish university qualification or the validation of partial studies, taking into account that both possibilities cannot simultaneously be requested.
If you choose to apply for the recognition as equivalent of the qualification and this request were refused, you could apply for the partial validation of your studies, provided that the refusal wasn't based on any of the grounds set out in article 5 of Royal Decree 285/2004 of February 20.
This Royal Decree regulates the conditions of recognition as equivalent and validation of foreign studies and qualifications (BOE March 4, 2004).
Foreign studies conducted whole or in part in Spain won't have official validity when centres lack authorization or when the teaching of the foreign degree which approval is requested weren't effectively implemented in the University or in the Foreign Higher Education Institution at the time of the qualification issue.