All these articles are used in front of SINGOLAR and MALE names.
The different is: when the name starts in pn, pt, gn, ps, x, y, z, s+cons YOU USE "LO".
For example: lo zaino (backpack), lo squalo (shark), lo scienziato (scientist), lo pneumatico (pneumatic).
In the other cases YOU USE "IL" but ever and only with MALE AND SINGOLAR names.
For example: il treno (train) il semaforo (traffic light) il cane (dog) il gatto (cat)
I hope iwas helpful to you.
Since I am learning English, if you want to share some opinions or works i am very interested abuot it.