what is Injection mold?  Injection mold is known as a mold tool made by mold co, which is utilized to make component in injection machine,  after mould design approved,the plastic material  (melt material can flow in the mold ) is injected into mold  where the material would be cool down there(there is water channel in the mold to quick the cooling time), open the mold tool to eject the part(the part will be stripped out of the mold).  The mold cavity and core  profile is a reflected version of  part.

In short:  injection mold is source of plastic molding and die-casting component

The injection mold is made of steel, which steel is usually P20H,S136H,2738,2316,420
It has  injection and ejection system, cooling system and housing system.
The mold lifespan is coming from 500 cycle times to 2,000,000 cycle times .

also some other mold co has another molding style”blow molding,rotational molding…