Shared security is one of Polkadot’s unique features. It basically means that all the parachains connected to this ecosystem leverage the Relay Chain’s high level of security.
Polkadot’s logic differs greatly from interchain protocols – where you build with bridges – because it offers its projects freedom while keeping them safe through the Relay Chain. In other words, Polkadot is like a safety net that allows projects with different purposes to build and evolve. Economic security is another important aspect of Polkadot: independent projects outside the ecosystem often struggle with economic security due to a low market cap, projects on Polkadot benefit from their direct connection to the Relay Chain, where all the transactions take place.