How check it's deployed?

[SC-One]

in the explainations: https://tact-by-example.org/06-contract-deploy-another , we have this:
When sending any message to a contract, we can attach its stateInit by specifying the code and data fields of the message. This will deploy the contract if it has not already been deployed. If the contract has already been deployed, these fields will be ignored.

Is that meaning it searches in all block chains to find the same address? or how it's doing? And if we send a value below the minimum requirement for storage, what happens?