Which styling product is used primarily to hold a hairstyle in place?

Hairspray is primarily designed to hold a hairstyle in place, making it the go-to product for achieving long-lasting hold. It typically contains polymers that provide a firm yet flexible hold without weighing down the hair. When applied, hairspray creates a protective shield around the hair strands, preventing frizz and maintaining the intended style throughout the day.

In contrast, while mousse and gel can help set styles, their primary functions vary. Mousse typically adds volume and body to hair, often enhancing curls or waves rather than providing maximum hold. Gel can create a sleek, wet look and offers hold, but it may also make hair crunchy if too much is applied. Conditioner, on the other hand, serves to moisturize and detangle the hair, leaving it soft rather than styled. Therefore, in the context of holding a hairstyle, hairspray is the most effective choice.