An election for the offices of President, Vice President, Presidential elector, and Congressional offices (Member of the U.S. Senate, and Member of the U.S. House of Representatives).
Delegates from the District of Columbia, and the territories of Guam, Virgin Islands, and American Samoa, and Resident Commissioner of the Commonwealth of Puerto Rico are also chosen in federal elections.
The U.S. holds several types of elections for federal offices including general, special, runoff and primary elections - these can all be federal elections intended to select, nominate and/or elect a candidate/s for federal offices.
The Uniformed and Overseas Citizens Absentee Voting Act (UOCAVA) establishes the right to vote for federal offices for U.S. overseas citizens - both civilian and miltary. This right to vote does NOT depend on maintaining a residence or property in the U.S. and is not lost over time.