Can I buy 0.5 ETF?

Could you please clarify for me? I'm a bit confused about the possibility of purchasing fractional shares. Is it actually feasible to buy just 0.5 of an ETF? Would that be allowed by the exchange or brokerage platform? And if so, how would that work in terms of ownership and trading? Also, are there any specific considerations or limitations I should be aware of when attempting to buy a fractional share like this? Thank you for your assistance in clarifying this matter for me.