A barrier to entry is any factor that makes it difficult or costly for new competitors to enter a particular market or industry. These barriers can be structural, strategic, legal, or financial, and they help protect established businesses from new entrants.
Examples include high start-up costs, strong brand loyalty among existing customers, patents and intellectual property, exclusive access to distribution channels, government regulations, and economies of scale that favour larger, established firms.
Barriers to entry can limit competition, allowing dominant players to maintain market share and pricing power. However, they can also reduce innovation and consumer choice if the market becomes too closed.