Candidate transactions of the form "Payer pays payee x bitcoins" are broadcast to this network; any Bitcoin server can validate these transactions, add them to its copy of the blockchain ledger, and then broadcast these additions to all other servers.
Candidate transactions of the form "Payer pays payee x bitcoins" are broadcast to this network using readily available software applications. Any Bitcoin server can validate these transactions, add them to its copy of the blockchain ledger, and then broadcast these ledger additions to all other servers.