A sharp object is any implement with at least one cutting edge, including but not limited to swords, daggers, knives, razor blades, scissors, and, if handled improperly, paper. Sharp objects are often pointy, but not always. In most cases, the sharp object must be regularly sharpened, lest the owner risk it becoming blunt.
The terms "knife" and "dagger" are often used interchangeably, but the connoisseur of sharp objects knows that a knife has one sharp edge while a dagger has two. Therefore, daggers are better for stabbing while knives are the first choice for people who prefer to inflict slicing or slashing damage.
Similarly, some swords are better for slicing or chopping than for stabbing. These include the cutlass, the falchion, some kinds of sabres, and the katana.