A protective put and a regular put option both involve buying a put option, but their purpose and overall strategy are different. A regular put is typically purchased as a standalone options position. The buyer expects the price of the underlying asset to decline and aims to profit from that decline. If the asset falls below the strike price, the put can increase in value, potentially generating a profit that offsets the option premium paid.

A protective put, on the other hand, is used primarily as a hedging strategy. An investor already owns the underlying stock and buys a put option on the same stock to protect against a significant decline in its price. The put establishes a minimum effective selling price, depending on the strike price, while allowing the investor to continue benefiting if the stock rises.

For example, suppose an investor owns 100 shares of a stock trading at $100 and buys a put with a $95 strike price. If the stock drops sharply, the put can gain value and help offset losses in the shares. If the stock rises, the investor can continue benefiting from the stock's upside, although the premium paid for the put reduces the overall return.

Therefore, the key difference is **purpose**. A regular put is commonly used to speculate on a decline or express a bearish view, while a protective put is designed to manage downside risk on an existing stock position. The protective put is often compared to insurance because the investor pays a premium to limit potential losses while retaining upside exposure.