I’m not trying to be condescending, it just helps me to understand your frame of reference. I'll do my best to explain.
On the bitcoin blockchain (base layer), the transaction hash (the same thing as the transaction ID) is the reference (you can think of it as a receipt) that proves a transaction is valid. It always has 64 characters (32 bytes). Even the Genesis block has one, from the first 50 bitcoins ever produced on the network. The hash is 4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b and you can check it on any bitcoin block explorer.
On the Lightning Network (second layer), there is a similar term called a payment hash, but it isn't itself validated on the blockchain. Instead, payments pass between nodes using channels. When you create an invoice for me to pay you, your wallet's node generates a payment hash of some secret data called a preimage. When I pay the invoice, the payment hash proves that you generated the invoice, and we can both use this as a receipt to verify that the transaction is valid. I just zapped you 21 sats, and the payment hash is 2f60255f5017ba6fdfe6d680b678858b60b4b6bef9973f8f9af54bc210d94a1e so you should be able to see that in your wallet.
Hopefully I described that well, and if not, someone else please jump in and correct or clarify.
There are a lot of tutorials and videos that explain these concepts better than I can. You can look for Andreas Antonopoulos or BTC Sessions on YouTube and start exploring there, and you should also read the book Inventing Bitcoin by Yan Pritzker. One of the best tools I recommend to start learning.
