Marketisation and the massification of higher education, alongside changes in research funding structures, have reshaped the nature of academic work and employment. The value generated by public research is estimated to be between three and eight times its initial investment over its life cycle. There are a wide variety of contractual bases for non-tenured researchers that vary substantially between institutions and national settings. As long ago as 1994, the UK Association of University Teachers report observed a range of career and employment disadvantages experienced by contract researchers. The nature of fixed-term research affects prospects for advancement in terms of tangible and intangible benefits and opportunities, including access to internal funding, and opportunities to gain important and valued skills that are typically required for achieving tenure and promotion. The chapter also presents an overview of the key concept discussed in this book.