A gold CFD is a leveraged contract with a broker that tracks the gold price, allowing precise sizing from one ounce, short exposure and instant execution, at the cost of broker counterparty risk and daily financing.
Physical bullion is owned metal with no leverage, no margin call and no broker counterparty, but carries a dealer premium, a wide retail buy-sell spread, storage and insurance costs, and cannot be sold short or sized precisely.
Gold ETFs sit between the two: bullion-backed securities that trade like shares with an annual management fee. Trading belongs in CFDs or futures judged by expectancy; ownership belongs in ETFs or bullion judged over years, and the two ledgers should be kept separate.