SPL token is the original token standard of the Solana blockchain - the equivalent of ERC-20 in the Ethereum family, defining how tokens are represented and transferred under Solana's account model. Its successor, Token-2022, extends it with program-level hooks: transfer fees, confidential transfers, and the authorities that regulated issuers need.
Solana-native tokenized assets, including the xStocks family, use these standards; the difference between them and an EVM token is plumbing, not economics.
Solana assets on U.CASH are SPL or Token-2022 tokens, with the standard stated per asset page and on every form of a tokenized stock that trades on Solana.
Every term behind the rails, the assets, and the settlement.