penetration

Penetration is a term that describes the act of entering or passing through a boundary, barrier, or boundary-like condition. It can refer to physical intrusion, such as a projectile breaching armor or a person moving through a barrier, as well as more abstract processes in science, technology, and strategy.

In anatomy and health, penetration can describe the process of entering a body cavity or tissue. In sexual health, it refers to the act of inserting one object or body part into another during sexual activity. Discussions about penetration in medical or sexual contexts emphasize consent, safety, and risk reduction, including protection against sexually transmitted infections and considerations of physical comfort and health.

In cybersecurity, penetration testing or pen testing is a controlled assessment that simulates real-world attacks to identify security weaknesses. It follows a structured workflow: planning and scoping, information gathering, vulnerability exploitation, and reporting of findings with recommendations for mitigation. Authorization and ethical guidelines are essential components.

In military, engineering, and materials science, penetration describes a projectile or force’s ability to breach defenses, armor, or barriers, as well as the study of how far particles, waves, or signals can travel into a material. Penetration depth is a common measure in fields such as toxicology, geology, and nondestructive testing.

In business, market penetration refers to the strategy of increasing a product’s share within an existing market, often through pricing, promotion, distribution, or product adjustments. The term’s exact meaning varies by discipline, but across contexts it generally denotes the act of crossing a boundary or entering a new domain.