A cash-secured put is a way to get paid to wait for a lower price. If the stock stays above the strike you keep the premium. If it falls below, you buy 100 shares at the strike, minus the premium collected, and now own a stock that just dropped.
This is the first half of the-wheel. The risk is the same as owning the stock from the strike downward.
Example: stock at $52. Sell the $50 put for $1.50 with $5,000 set aside. If the stock ends at $55, you keep $150. If it ends at $44, you own 100 shares at an effective $48.50 while the market price is $44.
Related: covered-call, the-wheel, put-option, assignment