International human resource management involves adapting HR practices like hiring, training, compensation, and performance evaluation to different country contexts. IHRM managers face greater complexity than domestic HR due to differing cultures, economic environments, and legal systems among countries. They must decide whether to employ managers from the home country, host country, or third countries, balancing communication with headquarters with local knowledge. Proper selection and training of expatriates is important to reduce costly expatriate failure. Cultural adaptation challenges like culture shock can also impact performance, so pre-departure preparation and support are needed.