There are three different types of shin guards in soccer and each one suits a different kind of player.
The first type: Slip-in Shin Guards.
As the name implies, these shin guards basically slip onto your feet. They are mostly used by soccer players who are already in their intermediate to high-level stages, since they are lightweight and they provide plenty of impact resistance and protection which can increase freedom of movement.
Slip in guards are also on the expensive side but well worth it if you can afford it. The freedom they provide with there light weight can be crucial when you are on the field.
The second type: Ankle Shin Guards.
This particular type of guards has extended padding that provides maximum protection from your shin to your ankles. It has elastic straps which extend to your ankles and wrap around your feet to lock them in place.
They are perfect for beginners as they are simple, easy to put on, cheap and are carried by almost every brand out there. So if you are buying for your kids or yourself who is just starting to play then these are the ones you want to get.
The top of an ankle shin guard has a velcro strap to keep it intact on your leg. Ankle shin guards are used mostly by beginners who are still practicing their kicking moves, since they are still prone to get injured without them.
Lastly, the Sock Style Shin Guards.
These shin guards are the least commonly used ones, since they do not really provide that much of a protection which defeats the point of having them.
A sock style shin guard combines a soccer sock and the guard into one package, which is why it comes at a lower price point than most shin guards. Sock style shin guards are mostly worn by players who just want convenience.
These can be perfect for if you are planning on playing with your friends and you know that nobody will be wearing cleats and there is low chance of injury. For actual games not so much.