The word 密码 (mì mǎ), meaning "password" or "code", is formed by combining two meaningful characters. The first, 密 (mì), conveys ideas of secrecy, confidentiality, and being closely guarded. The second, 码 (mǎ), denotes a sign, symbol, or numbered tag used for identification or representation. Together, they create a compound concept literally meaning "secret symbols" or "confidential signs", which perfectly encapsulates the idea of a system of concealed characters used for security and access.