Explain the meaning!

No. This means that what I have known for a long time, but forgot. But you can install exactly as many dies as there are corresponding connectors on the board.

the number of channels is 2 this means that the pitch memory can work in 2-channel in parallel by adding 2 memory cards. this is the norm for all pitches over a very long period of time. the exceptions are only 1366 where there are 3 channels and 2011 where 4.
roughly speaking, sequentially the pitch can add a lot of memory more often as much as there is on the mantboard. of course, if there are 2 slots on the motherboard, then 2. if there are 4 slots, they will work as (1 + 1) + (1 + 1).