black thing on chips

in most of the electronics products there is a black blob on the main chip. i have seen this black blob on handheld games and even on the LSI chip of a multimeter.

my question is that what is the use of this black blob. is it the same as the heat spreader of a microprocessor. and why is it black.

It is called "Chip On Board" or "COB" or "SoC" (System on Chip). It is a custom designed IC directly fabricated on to the PCB and the black thing protects silicon wafer from getting damaged. Black thing is a type of plastic. Actually I forgot its name.

thanx for your answer