Financial entitiesas defined in Article 2, points (a) to (t) vary widely in their size, structure, and internal organisation and in the nature and complexity of their activities. It is therefore necessary to take into account that diversity while imposing certain fundamental regulatory requirements which are appropriate for all financial entitiesas defined in Article 2, points (a) to (t) when developing the elements which a financial entity needs to determine and assess when subcontracting ICT servicesmeans digital and data services provided through ICT systems to one or more internal or external users on an ongoing basis, including hardware as a service and hardware services which includes the provision of technical support via software or firmware updates by the hardware provider, excluding traditional analogue telephone services; supporting critical or important functionsmeans a function, the disruption of which would materially impair the financial performance of a financial entity, or the soundness or continuity of its services and activities, or the discontinued, defective or failed performance of that function would materially impair the continuing compliance of a financial entity with the conditions and obligations of its authorisation, or with its other obligations under applicable financial services law; and to ensure that those requirements are applied in a manner that is proportionate.