I read elsewhere that if I lose my trezor than I can recover my wallet with a new trezor
but what if I lost my laptop also?
is this also recoverable?
If yes, how is the recovery done with just the 20 words seed?
does the Trezor company have a database which stores my seed and private keys and compares the two?
If no, then how can the wallet be recoverable if both trezor and laptop are lost?
Short answer: Maths.
Long answer: The seed actually contains enough data to (re)construct all your private keys, past and future.
Trezor itself only stores the seed. Whenever you need a key for something, Trezor generates it on-the-fly, using the seed as, well, seed, for the process. This means that every time you ask for a particular key (e.g., “show me address number 7 for account #1 of Bitcoin”), the same key is generated and used.
Get a new Trezor, input the same seed, and the same answers come out as before.