What is the oracle problem?

The oracle problem, or the 'smart contract connectivity problem', is a challenge faced by blockchains due to their inability to natively interact with external off-chain systems. This arises from the strong security protocols and consensus mechanisms used within the blockchain, which are effective for generating consensus on transactions but hinder access to real-world, subjective data. Blockchains focus on verifying transaction validity while limiting connections to off-chain systems, ensuring the network's continuous operation and deterministic results. To bridge the gap between on-chain and off-chain environments, an 'oracle' is needed; however, this must be highly decentralised to prevent manipulation and ensure the end-to-end security of smart contract execution.