What's the difference in usage between 氏名 (しめい) and 名前 (なまえ)?
I often see these two words used interchangeably, but more often than not I see 氏名 on websites. Is this a politeness difference or an actual word definition difference?
氏名 always refers to a person's full name, both family and given. It also has the connotation of "legal name."
名前 also refers to a person's full name—but it can also mean their given name, in the right context (for instance, "We gave the baby a name" or "I want you to call me by my name"). 名前 can also refer to the names of objects, while 氏名 cannot.
Both 氏名 and 名前 mean the full name of person except for the case of 名前 being used as the name of anything under the sun. 氏名 is also called 姓名 (せいめい). The literal translation of 氏 and 姓 is the name of a family or old clan like 藤原氏、源氏、平家、足利氏 and 名 is a name, primarily the first name like 太郎 and 花子.
氏名 and 姓名 are formal expressions of 名前, and used often in the heading of name entry box in legal and formal documents such as birth registration, passport, and resume. In application or entry forms for commercial purpose today, you are requested to fill in your name in “お名前” box more often than “ “氏名 or 姓名” specifications.