This involves the difference between the words themselves. Yes, this word has a defined meaning, that is, what attributes are given to the subject of the sentence. Although yes is sometimes used to indicate the past state, it is not strict. Department- describes the status only once and for a period of time. Yes, it's very different from the department. When using legal terms in contracts or agreements, legal terms cannot be ambiguous, so the strict usage is to use the system in legal documents.