theres basically 3 types of pistons generally used for engines..

1/ cast iron
cast iron are basically stock pistons...the good thing about them is that they dont expand much when heated up and they take very little time to heat up. this allows for tighter piston to wall clearance which basically eliminates piston to wall slap. they are also the weakest type of the 3.

2/ forged with low silicone content using 2618 aluminium
Example of the brand is Wiseco. this type is the strongest of all....the downside is that both types of forged pistons will expand MORE than cast iron pistons so will require greater piston to wall clearance. another downside is that they take longer to heatup and expand. so during cold starts, piston to wall slap is pretty common...at least til the pistons warm up. wall slaps can scratch ur sleeve.

3/ forged with high silicone content using 4032 aluminum
Supertec and CP uses these... a common trait of forged pistons is that they expand MORE than cast iron pistons so will require MORE piston to wall clearance. the bad thing is, they take longer to heat up and expand.. so during cold starts, piston to wall slap is common. again, wall slaps can scratch ur sleeve. this type of piston however, expands less than the one above. so u can get tighter piston to wall clearance and minimize wall slap. they are also not as strong as the one above but still significantly stronger than cast iron pistons.