Multicultural communication involves understanding different cultural backgrounds to effectively communicate across cultures. Culture, ethnicity, and acculturation are related but distinct, where culture refers to learned behaviors and ethnicity to ancestral background. Cultural and religious differences can affect healthcare through misunderstandings, but professionals can address diversity through cultural awareness and competency. Family culture influences patient education, while literacy issues like illiteracy present additional barriers that professionals should consider when assessing skills and readability levels to establish effective and helpful communication.