We elect a president for a 4-year term. A candidate can run for president as many times as he or she wants. The person can only be elected president for eight years, or two terms of four years each.
The Constitution says how many terms a president can serve. For example, President Dwight D. Eisenhower became president for the first time in 1953. Then he ran for president again. He won the election and, in 1957, became president for another four years.