The transaction is added to the blockchain and deemed "confirmed" if it successfully completes all validation checks. I hope this makes it more clear how nodes validate or confirm transactions on the block.
Wrong.
As I said in the first reply, transactions are confirmed by miners.
Transactions must be valid, so that they can be included in the blockchain, but it's not that a transaction is included in the blockchain once it's validated.
For a transaction being confirmed, it's required that a miner (or a mining pool) solves the proof of work problem, mines a block and includes that transaction in the block.
You misunderstood me, I believe we are saying the same thing,
Yes it's true that transactions are confirmed by miners, now what or who are miners?
Miners are nodes that work to add new blocks to the blockchain and are rewarded with bitcoin for doing so. So when I say
"they check for things like the digital signature of the transaction" I'm simply talking about the miners.
It's important to note that people often talk about Miners and Nodes together as they're same as one, which is wrong, in as much as Miners could be considered to be nodes that work to add new blocks to the blockchain by solving some complex mathematical problems ( Proof of Work), Nodes, on the other hand, are any computers that are connected to the network and are helping to verify and relay transactions. So, we could say that all miners are nodes, but not all nodes are miners.
And when I say
"The transaction is added to the blockchain and deemed "confirmed" if it successfully completes all validation checks. I hope this makes it more clear how nodes validate or confirm transactions on the block." what I mean is that the transactions are added to the blockchain AFTER they have been confirmed and has completed all validation checks.