The core idea
An exchange-traded fund holds a portfolio and trades on an exchange. Its holdings depend on the stated strategy.
A little more context
A sector or single-stock ETF can be concentrated. Read the holdings rather than assuming the label means broad exposure.
What to remember
ETF prices move during exchange sessions. Their market price can differ from the estimated value of their underlying holdings.
Pause and reflect: how would you explain this idea to someone who has never invested?