Beachhead comes from military strategy where it is used to denote the need to focus energy and resources on a small area to hold it as a stronghold. Such a strategy is useful for start-ups who focus on one market or one product to compete against conglomerates.
Diagrams

Originated from/Coined by
Normandy, 1944
Further Reading/ References
https://en.wikipedia.org/wiki/Beachhead
https://timberry.bplans.com/the-power-of-beachhead-strategy/
https://www.linkedin.com/pulse/4-elements-beachhead-strategy-sovita-chander
