Single channel RAM vs Dual channel RAM

[nagasahitya]

my motherboard(GIGABYTE GA-AM1M-S2H) has two single channel RAM slots.can i use 2*2GB memory modules, means each memory module in each slot or i have to use only 1*4GB memory module in one slot.what is the difference between dual channel RAM & Single channel RAM,is it is RAM spcefic or Motherboard specific.please explain me.

[David (PassMark)]

Dual channel interleaves access and is slightly faster as a result. But you should try and use identical sticks if you are doing dual channel.

[nagasahitya]

shall i use 2*2GB memory sticks in my GIGABYTE GA-AM1M-S2H motherboard