Demarcation (noun)

1. A line or boundary that marks the limit or extent of an area.
2. A distinction or separation between two things.

Origin:

Mid 17th century: from french démarcation, from démarquer "mark out".

Examples:

1. The demarcation between the two countries is clearly visible on the map.
2. The company's policy on overtime work was changed due to a demarcation dispute.
3. The demarcation of the city limits is determined by the state government.
4. The new law established a demarcation between public and private land.
5. The demarcation between acceptable and unacceptable behavior is not always clear.