The frame is sturdy, with a geometry similar to a mountain bike, but with a more upright seating position than a mountain bike - less strain on the arms and better visibility. Designed for longer journeys, often adapted for mounting various accessories: mudguards, racks.
Material - aluminium, the most common. Lighter than steel and stronger than carbon fibre. Used in various types of bicycles. It has the best price/weight ratio.
The chain is partially hidden under the chain guard or a scratch guard is placed on the frame. Usually left quite open for easy access when changing.
Plastic mudguards are often added to keep the overall weight of the bike to a minimum, to accommodate the optional luggage rack.
Saddle is narrower, harder (compared to city bikes) for a sportier seating position.
V-brake - easy to change, lightweight, inexpensive, but selecting brake pads to suit the conditions of use can give high performance.
Both dynamos for comfort and separate battery lights to keep the design lighter.
Child's bike - choose according to age and height. Specifications often include a recommended age range for the child with height frames as appropriate. These are usually the main and fairly accurate criteria for selecting a bicycle for a child, leaving only the attractiveness of the design.