Hi ther,
These come in kit model kit form of usually about 8-10 pieces per figure.
They're a nice inexpensive (about £12) little starter set in which you get enough parts to assemble six figures glue, paint & 2 brushes.

This video provides a good introduction:


Of course there's no hard & fast rules on building.. I personally use only what's included in the box & follow the instructions regarding the poses, trying to reproduce a good quality toy soldier like finish, but I've seen people at model shows really go to town with parts conversion, super detailing & painting to produce some very lifelike results.

The models themselves originally date from the 70's and were something of a revelation at the time. The concept is, that, by buying multiple sets you can create a near endless combination of poses.. there's a selection of different headgear & weapons included that aren't even shown in the instructions.

Some recent additions: