Dutch bikes are a style of city bicycles with a design that originates in The Netherlands, a country where the majority of the population uses a bicycle for everyday tasks. This means the bicycle is designed from the ground up for comfortable, durable transportation without speciality clothes or a fitness objective (though the Dutch are a relatively fit population, thanks in part to all the cycling.)
Dutch bikes have some key features that are unique to them.
Utility
Because they are designed for everyday transportation, Dutch bikes have features into the design that address these needs better than other designs.
Fully encased chain guard, skirt guard, and fenders: Using a bicycle as regular transport means being able to hop on your bike in regular clothes. The fully encased chain guard, skirt guard, and fenders allow riding without worry about grease, mud splatters, or clothing caught in gears and spokes.
Racks: Riding a bicycle around town isn't much fun if you can't pick up those vintage shoes you found or grab a bottle of wine and flowers for that dinner party. Racks get the load off your back so you can carry so much more.
Lights: Your life doesn't end at sunset and you bike should not leave you stranded. Dutch bikes have lights integrated into the bike and powered by your wheel so you are never left pedaling in the dark or getting your lights swiped.
Frame Lock: This is one those features that ought to be on a lot more bikes. A built-in lock when engaged makes the bike unrideable and is lockable to bike racks with an optional plug in heavy duty chain. Never be without a lock!
Durablity and Low Maintenance
Dutch bikes are designed to be left outside for months on end and still perform without need of maintenance. Internal gears and brakes mean nothing to get out of alignment, creak or rub. The encased chain ensures no rusty chain and puncture resistant tires make flats a rarity. The heavy duty frame takes a beating and keeps on going. Grandparents handing down bikes to their grand children are not an upcommon occurance.
Comfort
In The Netherlands, everyone from teenagers to 80 year olds ride bikes. This means the bikes are designed for the comfort and fitness level of regular people. An upright riding position and wide saddle provides a relaxing ride.
In addition to comfort, the upright seated position of the Dutch bike gives you a good view of the road while making you visible to cars. In fact, you are often riding higher than the tops of most cars. Built-in lighting and reflectors make more visible, especially after dark.
Style
With their iconic design, Dutch bikes look better than just about any bike on the road. Style shouldn't be the defining feature of a good transportation bike but having a bike that looks this good doesn't hurt. Think of it as one more reason to make you want to go for a ride.
Racks: Riding a bicycle around town isn't much fun if you can't pick up those vintage shoes you found or grab a bottle of wine and flowers for that dinner party. Racks get the load off your back so you can carry so much more. 
In addition to comfort, the upright seated position of the Dutch bike gives you a good view of the road while making you visible to cars. In fact, you are often riding higher than the tops of most cars. Built-in lighting and reflectors make more visible, especially after dark.
