What is the difference between the inner six-star bolt and the inner hexagon bolt?

Two types of screws/bolts are often found on machinery and equipment. Star screws are commonly found on imported brand equipment, such as the most imported electric tools I have ever seen. In addition to being more vulnerable, the two also have advantages in terms of wear and tear, and also serve as a special part to prevent the disassembly of non-professionals. Hexagon socket screws are now common, and are often seen when assembling furniture. They are cheaper to manufacture than star screws and are easy to use. The disadvantage is that when the diameter is less than 3mm, it is easy to damage. For the reason, as Lu Jun said, I have a bunch of wrenches that are rounded; the star screws compensate for the shortcomings of the hexagonal screws, especially in the screw head. In the case of a small diameter. However, the manufacturing cost and accuracy are difficult. The depth of contact of the screwdriver is small and it is not common in a narrow area. Therefore, I have not seen the L-type wrench and the large star screw of the screw head