TIME FRAME is a term used to describe a period of time, usually in reference to a specific event or project. ERA is a three letter word that refers to a long and distinct period of history, such as the Middle Ages or the Renaissance. YEAR is a four letter word that refers to a single calendar year, such as 2020 or 2021. Together, these two words can be used to describe a specific period of time, such as the 21st century or the Victorian ERA.