> For the complete documentation index, see [llms.txt](https://optim-finance.gitbook.io/optim-finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://optim-finance.gitbook.io/optim-finance/leviathan/english/core-concepts/instant-finality/liveness-and-safety.md).

# Liveness and Safety

The realization of instant finality in blockchain systems requires a careful balance between two core properties: liveness and safety.

Liveness refers to the ability of the system to continuously process transactions and add new blocks to the blockchain without interruption. A network with high liveness consistently processes transactions, ensuring the system remains active and responsive. However, a strong focus on liveness can sometimes compromise safety, particularly in systems lacking instant finality.

Safety, on the other hand, ensures that once a transaction is confirmed, it remains unaltered and non-reversible. In the context of instant finality, it means that a block, once added to the blockchain, becomes final and immutable. This aspect is critical to prevent double-spending and uphold the blockchain’s integrity. Systems prioritizing safety, especially those with instant finality, offer robust assurances that a confirmed transaction is permanently etched on the blockchain.

Striking a balance between liveness and safety is essential in designing blockchain networks. Systems claiming instant finality often lean towards safety, ensuring that once a transaction is included in a block and validated by the network, it becomes irreversible. This is typically achieved through consensus mechanisms that require a significant agreement among the network's validators, providing strong safety assurances.

However, prioritizing safety and instant finality can impact liveness, particularly in networks with a large number of validators or those that are highly decentralized.