Previous PoW coins use PoW mechanisms to choose trustless miners to pack those transactions, while in XDAG it will be another way to use PoW that is using PoW to detect double spending transactions without impacts.
In old times, only the longest main chain is kept, that means all the transactions are not packed in these blocks belong to longest main chain. Thus we have limited TPS in block chain. The ways to scaleling block chain would be increase the block size or shorten the period to generate blocks. Either way are proven not efficient
as we thought.
XDAG is trying in one different way.
XDAG uses UTXO-like models to process transactions.
Mining is simple, no big difference than other PoWs.