Your seed actually looks something like this:
It is the true starting point for your "wallet" and has the ability to recover your coins.
But why don't we save these instead of the 12-24 word "seed phrase"?
We could! But you can imagine how difficult that is to copy down, double-check, and re-enter. You'd be going over it 100 times to make sure its correct.
Your Seed "Phrase"
That's where "seed phrases" come in. The true name for a "seed phrase" is actually mnemonic phrase — a group of easy to remember words.
BIP39 or Bitcoin Improvement Proposal 39 describes a method where wallets can instead utilize a 12-24 word phrase and convert (with "math") into a seed which generates your wallet.
It's entire purpose and motivation was to make recovery easier and more human friendly.
Words are superior to just letters and numbers when it comes to human interaction. It's easier to write down, say, check, re-enter, store, etc.
Seeing a word spelled incorrectly is much easier to spot than remembering if you wrote a "b" or an "d".
Essentially something like this:
relief horror hammer sudden old hair wet arrive pulp infant expand poem
Can be turned into this:
(if your wallet knows how by knowing BIP39 method which fortunately, most wallets do).
That's a ton easier to read isn't it?
Not only that but it's easier to write down and it’s easier to spot an error. Checking it wouldn't take very long and you'd know immediately if a word was spelled incorrectly.
But doesn't that make it easier if someone else finds it?
Now I know quite a few people who are concerned about someone else stumbling upon their mnemonic phrase. Thus, they do some do some encryption, code, or fancy letter/number conversion or shuffling so if someone finds it, they wouldn't understand how to "crack their code" or know what it's for.
But turning your words back into letters/numbers truly defeats the purpose of BIP39 mnemonic phrases to make recovery more "human". Remember, the biggest security risk is not other people, it's yourself. You are more likely to not remember what you did and lose access.
If you're concerned about a third party stumbling upon your seed phrase, use a passphrase. With a passphrase, you need both your mnemonic phrase and the passphrase to access your coins. Passphrases were specifically made in such a case of a third party threat finding your seed phrase along with other benefits.