What's the meaning of die package and hermetic module?

Hi, I have a simple question about the semiconductor device's package. What's the meaning of die package? Is it different from the chip?

And what is the hermetic module? Does it enclosure by some packages also?

Thanks

Die is chip, but it can't be used directly, because the pins are very small and it is a plate. So it need to be packaged.
Usually, what you see of a chip is the die after packaged.
Besides, package can protect the die.

Thanks, jecyhale. So how can I use the device as "die"? If it cannot be mounted on PCB, how can we use it? Thanks.

Do you have use some chips on you PCB?
If not, you can open you handphone and you will find some black box which are the chips after packaged.
They have some pins like needles which can sealed on PCB.

So any chip can be used on PCBafter package.
And any chip must be packaged before used.

yes, in some cases, especially sensitive to cost , die is directly mounted on the pcb.
after bond all pads of die to pcb pad, the die will be cover with glue ( actually , I don't know how to describe this, since it is one kind of black glue) and then, the whole pcb will be placed to be heated (about 40min or so)

I believe it is special epoxy that have temperature expansion coefficient about the same as the board material to prevent cracking.