Is the Electrum seed compatible with other wallets? Apologies if this is a simple question - a newbie here!
I'm trying to understand backups. If I use Electrum to make a back up (including the 12 word seed password), will I then need to use Electrum to restore my BTC/ or can I use a different piece of software (like Exodus?).

What I mean is: are backups/restoring wallets dependent on the software you made the original back up on? or can you restore using any software as long as you have the 12 word seed?

I'm wondering about cold storage of wallets.

THANKS!
There are different "backup-standards".

Some use BIP39 (mnemonic) which lacks a flexible wordlist and versioning. It's used by Ledger, Trezor, Bitpay/Copay, etc.

Electrum uses a different – more flexible – mnemonic backup concept which is incompatible with BIP39.

There is also the BIP32 keypath which can be different among wallets. Example: you can restore a Trezor BIP39 mnemonic in iOS BreadWallet, but due to missing support of BIP44 in BreadWallet, the funds cannot be recovered there.

If you switch away from a wallet, consider sending all your funds to the new wallet (although this has some privacy implications, it's generally good for security due to the re-keying).

But as long as you keep your backup (seed / mnemonic), there will always be a (theoretical) option to recover your funds. If the wallet didn't stick to a standard and died (no maintenance, etc.), then you may need to contact an expert for a manual recovery.

If you use a mnemonic, make sure you use at least 24 words.