The passing of time is a measuring unit that dictates the length of time between two events. Any measurement, such as years, days, hours, minutes, and seconds can be used to measure time with respect to its point of origin.
Age is the measure of time. Time can be used to calculate how old someone is by counting the number of years, months, weeks, days, hours, minutes, and seconds they've been alive.
Time is a fascinating concept. We live within the confines of a 24-hour cycle and yet we have different words to describe how long something takes: years, months, days, hours, minutes, seconds.