The primary difference between medium hold and flexible hold hairsprays lies in the level of control they offer. Medium hold hairspray offers a stronger level of hold than flexible hold hairspray and is ideal for styles that require added volume and a bit more structure, yet still maintain some movement. It's perfect for taming flyaways and maintaining hairstyles that need a bit more stability.
On the other hand, flexible hold hairspray provides a lighter, more pliable hold that allows for a natural look and more movement. It's fantastic for hairstyles where you want to maintain a soft, touchable feel, such as loose waves or a casual updo.
So, while medium hold hairspray gives you a touch more control and structure, flexible hold hairspray emphasizes movement and a natural finish. The choice between the two ultimately depends on the style you're aiming for and your personal hair needs.