When you open a non-leveraged BUY (long) position on an ETF, you are investing in the underlying asset.*
eToro also offers additional functions using CFD trading. With CFDs, you can open SELL (short) positions and use leverage. Keep in mind that if you hold a CFD ETF position, you do not actually own the ETF. Any CFD trade will be marked 'CFD' in the trade line.
* From 22 October 2020, all non-EU ETF positions opened by users residing in the EU or UK are only available as CFDs.