At any any given time there is only one President of the United States.
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Grover Cleveland is the only one.
Only one at a time.
No, that is not a requirement.
Eight. Each term is 4 years. A president can serve a term and then get re-elected one time.
Presidents serve one term before they must be reelected.
State which one(s)
One
There is only one at a time.
One, Grover Clevelandd
Executive=President Presidents serve for 4 years, with possibility of one-time reelection. His cabinet goes with him after he leaves office (They too, serve 4 years, unless he kicks them out).
All presidents are typically eligible to serve more than one term.