Need help understanding the relationship between some wallets and software.

So with the whole "don't trust Ledger and/or Trezor" thing going on I started doing more research into how to properly secure and control my Bitcoin. I went down a rabbit hole and now I am a bit confused and cannot find the answers I am looking for (or I am not understanding the answers I am getting).

So for a hardware device, building a wallet that uses SeedSigner seems to be a happy middle ground for me. I understand that I need a wallet for that to interact with, for example Sparrow or Blue Wallet. I like the idea of Sparrow more so I looked into it more and it talks about how you can connect it to a Bitcoin Core node or to an Electrum wallet or server. This is where my confusion begins.

I just don't understand Electrum and how it interacts with everything. It seems like you can just not use Electrum and connect Sparrow to Bitcoin Core directly. It also seems like Sparrow gives you an option to use "Private Electrum", which I assume is the server, to connect to. However, I have also seen people talking about setting up an Electrum server to talk to Bitcoin Core, which Sparrow can do anyway.

Long story short, Electrum is confusing me and no information I find about it it solving my confusion. Would I even need it? Is it more secure? Is it a wallet or a server or both? Thanks in advanced.