Difference among BDC eCATT and LSMW

Hi guys,

May I have your attention please?

I encounter difficulities regarding the relation among the above Data Transfer Tools.

So far,I have learned a little about these tools, and done some data batch input from

local drive.I find the three tools can deal with the same thing. So my question is what

distinction exists among them since they are similar so much?

Thank you