The paper presents a series of useful perspectives to comprehend if and how the harmonisation process of social and occupation policies at the EU level has been developed and which key concepts are necessary to interpret its progress. The analysis thus proposes some considerations/definitions of the term «harmonisation», focusing on two main aspects: firstly the process of harmonisation in relation to the creation/stabilisation of the so-called «social European model'; secondly the harmonisation process in relation to the EU enlargement process to find out how the future new EU states have been helped/supported to harmonise their own policies on social and occupational matters and in which direction such a process of harmonisation has been targeted, towards which values and development models and with which results/prospects.