A bull call spread (buy a call, sell a higher call) or bear put spread costs less than the single long option and has less theta and vega exposure, in exchange for capping the gain at the short strike.
Debit spreads suit a view of a moderate move. If you expect an enormous move, the cap hurts; if you expect a small one, the reduced cost helps.
Example: stock at $50. Buy the $50 call for $3, sell the $55 call for $1.20. Debit $1.80 ($180). Max profit = $5 - $1.80 = $3.20 ($320) above $55; breakeven $51.80.
Related: vertical-spread, credit-spread, call-option, put-option