I just bought a Jackson SLS3 and i wanted to know for sure in which way the neck was constructed, particulary if the headstock is a separate piece attached to the rest of the neck or if it is all just one piece.
If anyone knows and could tell me i would greatly appreciate it, and thanks for your time

Jackson head stocks are bonded to the neck behind the 1st few frets. What you're seeing is normal. The truss rod within in the neck is mainly the reason.