The wedding was beautiful, and the marriage ceremony was held in a small chapel.

marriage 是名词，来自动词 marry（结婚），本义是"婚姻、结婚状态"。 ceremony 是名词，意思是"仪式、典礼"。 marriage ceremony 指"结婚仪式"，即婚礼上正式举行的仪式部分。