| vocabulary word | definition | example |
| A.D. | "Anno Domini," Latin for "in the year of the Lord," refers to a year occurring after the birth of Christ | Hawaii became a state in A.D. 1959. |
| B.C. | stands for "before Christ" and is used after a numeral to indicate a year occurring before the birth of Jesus Christ | The first Olympic games were held in 776 B.C. |
| B.C.E. | stands for "Before the Common Era" | B.C.E. is a time division that may be used in place of B.C. |
| C.E. | stands for "Common Era" | C.E. is a time division that may be used in place of A.D. |
| century | a period of 100 years | We are currently living in the twenty-first century. |
| circa | in approximately | The museum noted the silver platter was made circa 1780. |
| parallel time line | shows two different sets of events on the same line | The parallel time line showed the major events of 1950 - 2000 in Europe and Asia. |
| time line | a diagram showing the order in which events took place | The time line showed the dates that each state joined the Union. |