In Ethereum, when a node ‘broadcasts’ a transaction or block, what algorithm is used to broadcast that transaction or block to all the nodes? What are some resources I could use to learn about this algorithm and its use in Ethereum?

Note: This is not the same question as mine. Mine is much more in-depth.

In Ethereum, when a node ‘broadcasts’ a transaction or block, what algorithm is used to broadcast that transaction or block to all the nodes? Also, how does this algorithm discover peers? What are some resources I could use to learn about this algorithm and its use in Ethereum?

Note: This is not the same question as mine. Mine is much more in-depth.