Immigration, in legal practice, concerns the entry into, residence in and departure from a state by individuals who are not nationals of that state, and the regulation of their status, rights and obligations. It encompasses visa applications, leave to enter or remain, asylum and international protection, family and work migration, student routes, detention, removal and deportation, and related appeal and judicial review proceedings. In the UK, immigration is primarily governed by the Immigration Act 1971, the Nationality, Immigration and Asylum Act 2002, the Borders, Citizenship and Immigration Act 2009 and associated Immigration Rules, with case law further refining key concepts (e.g. “lawful residence”, “precarious status”, “proportionality”). In Ireland, immigration is regulated by instruments including the Immigration Act 1999, the Immigration Act 2003, the Immigration Act 2004 and the International Protection Act 2015, together with EU free movement and residence provisions where applicable. The term “immigration” itself is largely descriptive and used consistently across England & Wales, Scotland, Northern Ireland and Ireland. It is central to advisory, compliance and contentious work involving migrants, employers, educational institutions, family members and public authorities.