Mercenaries are individuals who are hired to fight in armed conflicts for financial gain rather than for political or ideological reasons. They often work for private military companies or directly for governments, and their services can include combat, training, and security operations. Mercenaries are typically not citizens of the country they are fighting for, which distinguishes them from regular soldiers. The use of mercenaries has a long history, dating back to ancient times when armies would hire foreign fighters. Today, their involvement raises ethical and legal questions, particularly regarding accountability and the rules of warfare, as outlined in international law, such as the Geneva Conventions.