Voting age is the age when a person is allowed to vote in political elections by governments.
Most countries set it at 18. Ages ranging from 16 to 21 exist. Iran is the only sovereignty to ever have a voting age below 16 in recent history. They set it at 15 until it was raised to 18 recently.
When the voting age was first established it was usually set at 21. In the later twentieth century most countries, including the United States, lowered it to 18. A few jurisdictions today, such as Austria and the Isle of Man, have lowered it to 16.
This topic connects up with various other age-related permissions, such as age limit on purchasing alcohol. and age of possible marriage. Use of terms such as "teenager" needs to be clear as to what the term covers.