How does electrum interact with the underlying bitcoind service? I am a bit confused regarding the bitcoind peers and Electrum X peers.
From what I understand, the electrum X protocol is built on top of the bitcoin blockchain, but I cannot quite wrap my head around on how exactly they interact.
I get it that electrum needs to have access to a bitcoind process in order to sync up its database, but what happens after the sync? Does the electrum client receive notifications about new transactions from other electrum peers, or does it still use underlying bitcoind mempool? Or both?
Can somebody explain on how exactly these 2 services interact?
Electrum Server is a fancy abstraction on top of bitcoind and a custom index of UTXO data. Client wallets connect to it and send queries for details about their wallet, using its own index Electrum Server requests the correct information from bitcoind and returns it to the client. The Electrum Server keeps its index up to date by continuously querying bitcoind for changes such as mempool updates or new blocks.

All communication with the wider Bitcoin network happens through bitcoind, including block updates and transaction broadcasts. For the purpose of this discussion, Electrum servers are standalone and completely unaware of one another, there is no cross communication between them.