We had a different name on that but the same meaning, that is a mnemonic phrase, or they called the 12 words seeds phrase or must be known in the name of a private key.  Upon creation of a wallet, you must write it down on a sheet of paper to have a backup of your wallet anytime even your computer used was crashed or damage.  So now, without the private key, you can't able to open your wallet, it should have a password and the private key must be kept safe.

Try to explore on this board, Beginners & Help, there's basic information regarding Bitcoin wallet there on how to create and how to recover your wallet through your private key or seed phrase.

Anyway, welcome to the Bitcointalk forum, here, you will learn a lot, and next time you were handling Bitcoin with proper knowledge of storing your crypto, a digital asset.

I am assuming you re-installed your operating system? A couple Qs. I think we will be able to help better if we have clarity on these.

Do you recall ever creating a backup of your "wallet.dat" file?

Are you still using the same hard drive?

And what did you choose as your data directory when you installed Bitcoin Core last time? Did you keep it as default (%APPDATA%\Bitcoin) or choose a different drive/location. Your "wallet.dat" file can usually be found in that directory.

Assuming you didn't create a backup previously nor can find the old "wallet.dat" in your hard drive then it would be a little tougher. All hope is not lost though, because if you're using the same hard drive then with some luck you might be able to recover the old "wallet.dat" file with a data recovery tool.

Bitcoin core doesn't support seed phrase at all.

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To OP:

What do you mean by crash? Have you lost all your files?
If you are using windows and you have access to your files, the wallet file should be found in the following location.

If the passphrase is correct, you should be able to open your wallet.

Note that the passphrase can only be used to decrypt your wallet file. If you don't have your wallet file, that's useless.
For accessing your fund without any need to the wallet file, you need the private key.

As long the HDD is still fine you can still make out some recoveries of the files inside it. As long you do know the password then it wont really be needing some seed.

Yes I installed Windows 10 overtop of itself but chose the option to keep no files.

I do not recall creating a wallet.dat file, but if it was a default option I would gone along with it.

Yes I am using the same hard-drive.

I don't recall which directory I installed Bitcoin core to but it would have been whatever the default is.

Are there any data recovery tools you recommend?

Okay, your issue will require a painstaking process to get your wallet back. And since there is no customer support for cryptocurrency, you will not be able to regain access to it through conventional means. I myself have no idea how this works and what you can do to fix your issue, but you may wanna try EASEUS recovery software, it had worked wonders for files I have lost in the past, I hope it work on yours too

Unfortunately the only way you have is to use a recovery tool, a similar thing happened to me years ago and saved me the "EaseUS" tool but there are also others around very reliable, i wish you the best of luck in recovery the wallet file.