Explain to me briefly what the hide function is actually doing in jQuery withi the CSS.

This is a specific technical question. The interviewer is asking you to define the function of a single command within the cascading style sheet, or CSS. As the interview progresses, the technical questions will become more specific and more difficult. This is a positive sign that the interviewer is gaining confidence in your skills and is willing to dig deeper to determine just how much you know. It is advisable to review the commands you typically use when developing a web page before the interview.